diff --git a/toolchain/check/testdata/alias/no_prelude/basics.carbon b/toolchain/check/testdata/alias/basics.carbon
similarity index 97%
rename from toolchain/check/testdata/alias/no_prelude/basics.carbon
rename to toolchain/check/testdata/alias/basics.carbon
index 85f7fac57984..8ebdfa4169bc 100644
--- a/toolchain/check/testdata/alias/no_prelude/basics.carbon
+++ b/toolchain/check/testdata/alias/basics.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/no_prelude/basics.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/basics.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/no_prelude/basics.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/basics.carbon
 
 // --- alias.carbon
 
diff --git a/toolchain/check/testdata/alias/no_prelude/export_name.carbon b/toolchain/check/testdata/alias/export_name.carbon
similarity index 98%
rename from toolchain/check/testdata/alias/no_prelude/export_name.carbon
rename to toolchain/check/testdata/alias/export_name.carbon
index d2e3b58bfe04..f3d132d7abdc 100644
--- a/toolchain/check/testdata/alias/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/alias/export_name.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/no_prelude/export_name.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/export_name.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/no_prelude/export_name.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/export_name.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/alias/no_prelude/import.carbon b/toolchain/check/testdata/alias/import.carbon
similarity index 98%
rename from toolchain/check/testdata/alias/no_prelude/import.carbon
rename to toolchain/check/testdata/alias/import.carbon
index 82508f7d5c87..925c90899272 100644
--- a/toolchain/check/testdata/alias/no_prelude/import.carbon
+++ b/toolchain/check/testdata/alias/import.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/no_prelude/import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/no_prelude/import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/import.carbon
 
 // --- class1.carbon
 
diff --git a/toolchain/check/testdata/alias/no_prelude/import_access.carbon b/toolchain/check/testdata/alias/import_access.carbon
similarity index 97%
rename from toolchain/check/testdata/alias/no_prelude/import_access.carbon
rename to toolchain/check/testdata/alias/import_access.carbon
index b68c33846388..8bb9b826a57c 100644
--- a/toolchain/check/testdata/alias/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/alias/import_access.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/no_prelude/import_access.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/import_access.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/no_prelude/import_access.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/import_access.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/alias/no_prelude/import_order.carbon b/toolchain/check/testdata/alias/import_order.carbon
similarity index 98%
rename from toolchain/check/testdata/alias/no_prelude/import_order.carbon
rename to toolchain/check/testdata/alias/import_order.carbon
index ffb5e1c0a34d..7c85511cb798 100644
--- a/toolchain/check/testdata/alias/no_prelude/import_order.carbon
+++ b/toolchain/check/testdata/alias/import_order.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/no_prelude/import_order.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/import_order.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/no_prelude/import_order.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/import_order.carbon
 
 // --- a.carbon
 
diff --git a/toolchain/check/testdata/alias/no_prelude/in_namespace.carbon b/toolchain/check/testdata/alias/in_namespace.carbon
similarity index 92%
rename from toolchain/check/testdata/alias/no_prelude/in_namespace.carbon
rename to toolchain/check/testdata/alias/in_namespace.carbon
index 4b06b8436a12..5549d844ebfb 100644
--- a/toolchain/check/testdata/alias/no_prelude/in_namespace.carbon
+++ b/toolchain/check/testdata/alias/in_namespace.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/no_prelude/in_namespace.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/in_namespace.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/no_prelude/in_namespace.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/in_namespace.carbon
 
 // --- in_namespace.carbon
 
diff --git a/toolchain/check/testdata/alias/no_prelude/preserve_in_type_printing.carbon b/toolchain/check/testdata/alias/preserve_in_type_printing.carbon
similarity index 92%
rename from toolchain/check/testdata/alias/no_prelude/preserve_in_type_printing.carbon
rename to toolchain/check/testdata/alias/preserve_in_type_printing.carbon
index 88fbd1688ce7..803bd2e668ba 100644
--- a/toolchain/check/testdata/alias/no_prelude/preserve_in_type_printing.carbon
+++ b/toolchain/check/testdata/alias/preserve_in_type_printing.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/no_prelude/preserve_in_type_printing.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/alias/preserve_in_type_printing.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/no_prelude/preserve_in_type_printing.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/alias/preserve_in_type_printing.carbon
 
 // --- fail_alias_nested_in_type.carbon
 
diff --git a/toolchain/check/testdata/array/no_prelude/basics.carbon b/toolchain/check/testdata/array/basics.carbon
similarity index 99%
rename from toolchain/check/testdata/array/no_prelude/basics.carbon
rename to toolchain/check/testdata/array/basics.carbon
index fd5cae291412..3e532c10ce4c 100644
--- a/toolchain/check/testdata/array/no_prelude/basics.carbon
+++ b/toolchain/check/testdata/array/basics.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/array/no_prelude/basics.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/array/basics.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/no_prelude/basics.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/basics.carbon
 
 // --- assign_var.carbon
 
diff --git a/toolchain/check/testdata/array/no_prelude/element_mismatches.carbon b/toolchain/check/testdata/array/element_mismatches.carbon
similarity index 92%
rename from toolchain/check/testdata/array/no_prelude/element_mismatches.carbon
rename to toolchain/check/testdata/array/element_mismatches.carbon
index 1e4f98f794c0..d167c7bd304e 100644
--- a/toolchain/check/testdata/array/no_prelude/element_mismatches.carbon
+++ b/toolchain/check/testdata/array/element_mismatches.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/array/no_prelude/element_mismatches.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/array/element_mismatches.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/no_prelude/element_mismatches.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/array/element_mismatches.carbon
 
 // --- fail_arg_wrong_type.carbon
 
diff --git a/toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges.carbon b/toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon
similarity index 98%
rename from toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges.carbon
rename to toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon
index 7c546e08e8f3..f77f52edf6f8 100644
--- a/toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges.carbon
+++ b/toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon
@@ -9,9 +9,9 @@
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/dump_sem_ir_ranges.carbon
 
 // --- function.carbon
 
diff --git a/toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_ignore.carbon b/toolchain/check/testdata/basics/dump_sem_ir_ranges_ignore.carbon
similarity index 88%
rename from toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_ignore.carbon
rename to toolchain/check/testdata/basics/dump_sem_ir_ranges_ignore.carbon
index 3148d88e040e..8a126a530e3e 100644
--- a/toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_ignore.carbon
+++ b/toolchain/check/testdata/basics/dump_sem_ir_ranges_ignore.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --dump-sem-ir-ranges=ignore
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=ignore
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_ignore.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/dump_sem_ir_ranges_ignore.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_ignore.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/dump_sem_ir_ranges_ignore.carbon
 
 // --- with-range.carbon
 
diff --git a/toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_only.carbon b/toolchain/check/testdata/basics/dump_sem_ir_ranges_only.carbon
similarity index 85%
rename from toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_only.carbon
rename to toolchain/check/testdata/basics/dump_sem_ir_ranges_only.carbon
index 42502f80919a..c10de97afa1c 100644
--- a/toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_only.carbon
+++ b/toolchain/check/testdata/basics/dump_sem_ir_ranges_only.carbon
@@ -5,11 +5,13 @@
 // This tests `--dump-sem-ir-range=only` behavior, which is set implicitly by
 // file_test.
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_only.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/dump_sem_ir_ranges_only.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/dump_sem_ir_ranges_only.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/dump_sem_ir_ranges_only.carbon
 
 // --- with-range.carbon
 
diff --git a/toolchain/check/testdata/basics/no_prelude/duplicate_name_same_line.carbon b/toolchain/check/testdata/basics/duplicate_name_same_line.carbon
similarity index 58%
rename from toolchain/check/testdata/basics/no_prelude/duplicate_name_same_line.carbon
rename to toolchain/check/testdata/basics/duplicate_name_same_line.carbon
index 90e51653cc75..b3efe7ec3f69 100644
--- a/toolchain/check/testdata/basics/no_prelude/duplicate_name_same_line.carbon
+++ b/toolchain/check/testdata/basics/duplicate_name_same_line.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/duplicate_name_same_line.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/duplicate_name_same_line.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/duplicate_name_same_line.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/duplicate_name_same_line.carbon
 
 fn A() {
   if (true) {
@@ -31,28 +33,28 @@ fn A() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !if.then:
 // CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %n.patt.loc16_9: %pattern_type = binding_pattern n [concrete]
-// CHECK:STDOUT:     %n.var_patt.loc16_5: %pattern_type = var_pattern %n.patt.loc16_9 [concrete]
+// CHECK:STDOUT:     %n.patt.loc18_9: %pattern_type = binding_pattern n [concrete]
+// CHECK:STDOUT:     %n.var_patt.loc18_5: %pattern_type = var_pattern %n.patt.loc18_9 [concrete]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %n.var.loc16_5: ref %empty_tuple.type = var %n.var_patt.loc16_5
-// CHECK:STDOUT:   %.loc16_13.1: type = splice_block %.loc16_13.3 [concrete = constants.%empty_tuple.type] {
-// CHECK:STDOUT:     %.loc16_13.2: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc16_13.3: type = converted %.loc16_13.2, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:   %n.var.loc18_5: ref %empty_tuple.type = var %n.var_patt.loc18_5
+// CHECK:STDOUT:   %.loc18_13.1: type = splice_block %.loc18_13.3 [concrete = constants.%empty_tuple.type] {
+// CHECK:STDOUT:     %.loc18_13.2: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc18_13.3: type = converted %.loc18_13.2, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %n.loc16_9: ref %empty_tuple.type = bind_name n, %n.var.loc16_5
+// CHECK:STDOUT:   %n.loc18_9: ref %empty_tuple.type = bind_name n, %n.var.loc18_5
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:
 // CHECK:STDOUT: !if.else:
 // CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %n.patt.loc16_29: %pattern_type = binding_pattern n [concrete]
-// CHECK:STDOUT:     %n.var_patt.loc16_25: %pattern_type = var_pattern %n.patt.loc16_29 [concrete]
+// CHECK:STDOUT:     %n.patt.loc18_29: %pattern_type = binding_pattern n [concrete]
+// CHECK:STDOUT:     %n.var_patt.loc18_25: %pattern_type = var_pattern %n.patt.loc18_29 [concrete]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %n.var.loc16_25: ref %empty_tuple.type = var %n.var_patt.loc16_25
-// CHECK:STDOUT:   %.loc16_33.1: type = splice_block %.loc16_33.3 [concrete = constants.%empty_tuple.type] {
-// CHECK:STDOUT:     %.loc16_33.2: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc16_33.3: type = converted %.loc16_33.2, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:   %n.var.loc18_25: ref %empty_tuple.type = var %n.var_patt.loc18_25
+// CHECK:STDOUT:   %.loc18_33.1: type = splice_block %.loc18_33.3 [concrete = constants.%empty_tuple.type] {
+// CHECK:STDOUT:     %.loc18_33.2: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc18_33.3: type = converted %.loc18_33.2, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %n.loc16_29: ref %empty_tuple.type = bind_name n, %n.var.loc16_25
+// CHECK:STDOUT:   %n.loc18_29: ref %empty_tuple.type = bind_name n, %n.var.loc18_25
 // CHECK:STDOUT:   <elided>
 // CHECK:STDOUT:
 // CHECK:STDOUT: !if.done:
diff --git a/toolchain/check/testdata/basics/no_prelude/empty.carbon b/toolchain/check/testdata/basics/empty.carbon
similarity index 81%
rename from toolchain/check/testdata/basics/no_prelude/empty.carbon
rename to toolchain/check/testdata/basics/empty.carbon
index 438437437260..553ba6521aa5 100644
--- a/toolchain/check/testdata/basics/no_prelude/empty.carbon
+++ b/toolchain/check/testdata/basics/empty.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/empty.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/empty.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/empty.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/empty.carbon
 
 // --- empty.carbon
 
diff --git a/toolchain/check/testdata/basics/no_prelude/multi_error.carbon b/toolchain/check/testdata/basics/multi_error.carbon
similarity index 91%
rename from toolchain/check/testdata/basics/no_prelude/multi_error.carbon
rename to toolchain/check/testdata/basics/multi_error.carbon
index e1c95c7c09fc..65547d6c7a12 100644
--- a/toolchain/check/testdata/basics/no_prelude/multi_error.carbon
+++ b/toolchain/check/testdata/basics/multi_error.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/multi_error.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/multi_error.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/multi_error.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/multi_error.carbon
 
 // --- fail_multi_error.carbon
 
diff --git a/toolchain/check/testdata/basics/no_prelude/name_lookup.carbon b/toolchain/check/testdata/basics/name_lookup.carbon
similarity index 91%
rename from toolchain/check/testdata/basics/no_prelude/name_lookup.carbon
rename to toolchain/check/testdata/basics/name_lookup.carbon
index 733109796023..caf65865a104 100644
--- a/toolchain/check/testdata/basics/no_prelude/name_lookup.carbon
+++ b/toolchain/check/testdata/basics/name_lookup.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/name_lookup.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/name_lookup.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/name_lookup.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/name_lookup.carbon
 
 // --- fail_not_found.carbon
 
diff --git a/toolchain/check/testdata/basics/no_prelude/raw_identifier.carbon b/toolchain/check/testdata/basics/raw_identifier.carbon
similarity index 96%
rename from toolchain/check/testdata/basics/no_prelude/raw_identifier.carbon
rename to toolchain/check/testdata/basics/raw_identifier.carbon
index b5e595374e13..92dc9665e92c 100644
--- a/toolchain/check/testdata/basics/no_prelude/raw_identifier.carbon
+++ b/toolchain/check/testdata/basics/raw_identifier.carbon
@@ -2,13 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/raw_identifier.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/raw_identifier.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/raw_identifier.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/raw_identifier.carbon
 
 fn A(n: ()) -> () {
   return r#n;
diff --git a/toolchain/check/testdata/basics/no_prelude/verbose.carbon b/toolchain/check/testdata/basics/verbose.carbon
similarity index 88%
rename from toolchain/check/testdata/basics/no_prelude/verbose.carbon
rename to toolchain/check/testdata/basics/verbose.carbon
index 3d61158db1b4..a98fddeb9c06 100644
--- a/toolchain/check/testdata/basics/no_prelude/verbose.carbon
+++ b/toolchain/check/testdata/basics/verbose.carbon
@@ -6,9 +6,9 @@
 //
 // Only checks a couple statements in order to minimize manual update churn.
 // To test this file alone, run:
-//   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/no_prelude/verbose.carbon
+//   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/basics/verbose.carbon
 // To dump output, run:
-//   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/no_prelude/verbose.carbon
+//   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/basics/verbose.carbon
 // NOAUTOUPDATE
 // SET-CHECK-SUBSET
 // CHECK:STDERR: Node Push 0: FunctionIntroducer -> <none>
diff --git a/toolchain/check/testdata/builtins/no_prelude/no_op.carbon b/toolchain/check/testdata/builtins/no_op.carbon
similarity index 97%
rename from toolchain/check/testdata/builtins/no_prelude/no_op.carbon
rename to toolchain/check/testdata/builtins/no_op.carbon
index 30e0aa0b42e9..1c28c0422dff 100644
--- a/toolchain/check/testdata/builtins/no_prelude/no_op.carbon
+++ b/toolchain/check/testdata/builtins/no_op.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/builtins/no_prelude/no_op.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/builtins/no_op.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/builtins/no_prelude/no_op.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/builtins/no_op.carbon
 
 // --- no_op.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/comp_time_field.carbon b/toolchain/check/testdata/class/comp_time_field.carbon
similarity index 95%
rename from toolchain/check/testdata/class/no_prelude/comp_time_field.carbon
rename to toolchain/check/testdata/class/comp_time_field.carbon
index 2222eb318a00..3aa67e388527 100644
--- a/toolchain/check/testdata/class/no_prelude/comp_time_field.carbon
+++ b/toolchain/check/testdata/class/comp_time_field.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/comp_time_field.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/comp_time_field.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/comp_time_field.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/comp_time_field.carbon
 
 // --- fail_let.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/export_name.carbon b/toolchain/check/testdata/class/export_name.carbon
similarity index 96%
rename from toolchain/check/testdata/class/no_prelude/export_name.carbon
rename to toolchain/check/testdata/class/export_name.carbon
index bc9eb09e8626..25f1ac6fbad0 100644
--- a/toolchain/check/testdata/class/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/class/export_name.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/export_name.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/export_name.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/export_name.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/export_name.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/class/no_prelude/extern.carbon b/toolchain/check/testdata/class/extern.carbon
similarity index 99%
rename from toolchain/check/testdata/class/no_prelude/extern.carbon
rename to toolchain/check/testdata/class/extern.carbon
index 29a5cacb3174..0e9d8fc2a932 100644
--- a/toolchain/check/testdata/class/no_prelude/extern.carbon
+++ b/toolchain/check/testdata/class/extern.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/extern.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/extern.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/extern.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/extern.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/class/no_prelude/extern_library.carbon b/toolchain/check/testdata/class/extern_library.carbon
similarity index 85%
rename from toolchain/check/testdata/class/no_prelude/extern_library.carbon
rename to toolchain/check/testdata/class/extern_library.carbon
index a6601e09b872..c7b74a7259c8 100644
--- a/toolchain/check/testdata/class/no_prelude/extern_library.carbon
+++ b/toolchain/check/testdata/class/extern_library.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/extern_library.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/extern_library.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/extern_library.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/extern_library.carbon
 
 // --- fail_todo.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/fail_abstract_in_struct.carbon b/toolchain/check/testdata/class/fail_abstract_in_struct.carbon
similarity index 99%
rename from toolchain/check/testdata/class/no_prelude/fail_abstract_in_struct.carbon
rename to toolchain/check/testdata/class/fail_abstract_in_struct.carbon
index b3970e7bb581..458646a1ffa3 100644
--- a/toolchain/check/testdata/class/no_prelude/fail_abstract_in_struct.carbon
+++ b/toolchain/check/testdata/class/fail_abstract_in_struct.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/fail_abstract_in_struct.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/fail_abstract_in_struct.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/fail_abstract_in_struct.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/fail_abstract_in_struct.carbon
 
 // --- fail_abstract_field.carbon
 library "[[@TEST_NAME]]";
diff --git a/toolchain/check/testdata/class/no_prelude/fail_error_recovery.carbon b/toolchain/check/testdata/class/fail_error_recovery.carbon
similarity index 95%
rename from toolchain/check/testdata/class/no_prelude/fail_error_recovery.carbon
rename to toolchain/check/testdata/class/fail_error_recovery.carbon
index db2a4f913478..f3b0ef82ab98 100644
--- a/toolchain/check/testdata/class/no_prelude/fail_error_recovery.carbon
+++ b/toolchain/check/testdata/class/fail_error_recovery.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/fail_error_recovery.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/fail_error_recovery.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/fail_error_recovery.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/fail_error_recovery.carbon
 
 // --- fail_virtual_fn_in_invalid_context.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon b/toolchain/check/testdata/class/generic_vs_params.carbon
similarity index 99%
rename from toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon
rename to toolchain/check/testdata/class/generic_vs_params.carbon
index 501453b357b1..5a2077a63f09 100644
--- a/toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon
+++ b/toolchain/check/testdata/class/generic_vs_params.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/generic_vs_params.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/generic_vs_params.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/generic_vs_params.carbon
 
 // --- params.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/implicit_import.carbon b/toolchain/check/testdata/class/implicit_import.carbon
similarity index 98%
rename from toolchain/check/testdata/class/no_prelude/implicit_import.carbon
rename to toolchain/check/testdata/class/implicit_import.carbon
index b05c373dc182..56bed0164c25 100644
--- a/toolchain/check/testdata/class/no_prelude/implicit_import.carbon
+++ b/toolchain/check/testdata/class/implicit_import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/implicit_import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/implicit_import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/implicit_import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/implicit_import.carbon
 
 // --- basic.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/import_access.carbon b/toolchain/check/testdata/class/import_access.carbon
similarity index 99%
rename from toolchain/check/testdata/class/no_prelude/import_access.carbon
rename to toolchain/check/testdata/class/import_access.carbon
index ba56c30ae13d..293179637827 100644
--- a/toolchain/check/testdata/class/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/class/import_access.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/import_access.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/import_access.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/import_access.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/import_access.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/class/no_prelude/indirect_import_member.carbon b/toolchain/check/testdata/class/indirect_import_member.carbon
similarity index 99%
rename from toolchain/check/testdata/class/no_prelude/indirect_import_member.carbon
rename to toolchain/check/testdata/class/indirect_import_member.carbon
index 723a023df6e9..252972044470 100644
--- a/toolchain/check/testdata/class/no_prelude/indirect_import_member.carbon
+++ b/toolchain/check/testdata/class/indirect_import_member.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/indirect_import_member.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/indirect_import_member.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/indirect_import_member.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/indirect_import_member.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/class/no_prelude/method_access.carbon b/toolchain/check/testdata/class/method_access.carbon
similarity index 95%
rename from toolchain/check/testdata/class/no_prelude/method_access.carbon
rename to toolchain/check/testdata/class/method_access.carbon
index fffada872320..e2f71570c65a 100644
--- a/toolchain/check/testdata/class/no_prelude/method_access.carbon
+++ b/toolchain/check/testdata/class/method_access.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/method_access.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/method_access.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/method_access.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/method_access.carbon
 
 // --- fail_multiple_bindings.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/name_poisoning.carbon b/toolchain/check/testdata/class/name_poisoning.carbon
similarity index 97%
rename from toolchain/check/testdata/class/no_prelude/name_poisoning.carbon
rename to toolchain/check/testdata/class/name_poisoning.carbon
index 2d1bbad317eb..d5df6730ad66 100644
--- a/toolchain/check/testdata/class/no_prelude/name_poisoning.carbon
+++ b/toolchain/check/testdata/class/name_poisoning.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/name_poisoning.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/name_poisoning.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/name_poisoning.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/name_poisoning.carbon
 
 // --- no_poison.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon b/toolchain/check/testdata/class/no_definition_in_impl_file.carbon
similarity index 96%
rename from toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon
rename to toolchain/check/testdata/class/no_definition_in_impl_file.carbon
index 0c7ed3493bce..9e27a94269c3 100644
--- a/toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon
+++ b/toolchain/check/testdata/class/no_definition_in_impl_file.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_definition_in_impl_file.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/no_definition_in_impl_file.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_definition_in_impl_file.carbon
 
 // --- decl_in_api_definition_in_impl.carbon
 
diff --git a/toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon b/toolchain/check/testdata/class/syntactic_merge.carbon
similarity index 99%
rename from toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon
rename to toolchain/check/testdata/class/syntactic_merge.carbon
index 1f96003a9516..71a26ca4690a 100644
--- a/toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon
+++ b/toolchain/check/testdata/class/syntactic_merge.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/class/syntactic_merge.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/no_prelude/syntactic_merge.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/syntactic_merge.carbon
 
 // --- basic.carbon
 
diff --git a/toolchain/check/testdata/const/no_prelude/import.carbon b/toolchain/check/testdata/const/import.carbon
similarity index 96%
rename from toolchain/check/testdata/const/no_prelude/import.carbon
rename to toolchain/check/testdata/const/import.carbon
index f83f41025413..66db2d779ef8 100644
--- a/toolchain/check/testdata/const/no_prelude/import.carbon
+++ b/toolchain/check/testdata/const/import.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/const/no_prelude/import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/const/import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/const/no_prelude/import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/const/import.carbon
 
 // --- implicit.carbon
 library "[[@TEST_NAME]]";
diff --git a/toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon b/toolchain/check/testdata/function/builtin/adapted_type.carbon
similarity index 98%
rename from toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon
rename to toolchain/check/testdata/function/builtin/adapted_type.carbon
index 686c1d860115..69cfc6bd8f65 100644
--- a/toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon
+++ b/toolchain/check/testdata/function/builtin/adapted_type.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/builtin/adapted_type.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/no_prelude/adapted_type.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/adapted_type.carbon
 
 // --- adapt.carbon
 
diff --git a/toolchain/check/testdata/function/builtin/no_prelude/call_from_operator.carbon b/toolchain/check/testdata/function/builtin/call_from_operator.carbon
similarity index 99%
rename from toolchain/check/testdata/function/builtin/no_prelude/call_from_operator.carbon
rename to toolchain/check/testdata/function/builtin/call_from_operator.carbon
index 6983b4e54fef..4e2b46fe43df 100644
--- a/toolchain/check/testdata/function/builtin/no_prelude/call_from_operator.carbon
+++ b/toolchain/check/testdata/function/builtin/call_from_operator.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/builtin/no_prelude/call_from_operator.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/builtin/call_from_operator.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/no_prelude/call_from_operator.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/call_from_operator.carbon
 
 // --- core.carbon
 
diff --git a/toolchain/check/testdata/function/builtin/no_prelude/import.carbon b/toolchain/check/testdata/function/builtin/import.carbon
similarity index 99%
rename from toolchain/check/testdata/function/builtin/no_prelude/import.carbon
rename to toolchain/check/testdata/function/builtin/import.carbon
index 7e672356609e..c2afad7f5315 100644
--- a/toolchain/check/testdata/function/builtin/no_prelude/import.carbon
+++ b/toolchain/check/testdata/function/builtin/import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/builtin/no_prelude/import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/builtin/import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/no_prelude/import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/import.carbon
 
 // --- core.carbon
 
diff --git a/toolchain/check/testdata/function/call/no_prelude/empty_struct.carbon b/toolchain/check/testdata/function/call/empty_struct.carbon
similarity index 94%
rename from toolchain/check/testdata/function/call/no_prelude/empty_struct.carbon
rename to toolchain/check/testdata/function/call/empty_struct.carbon
index a81032ffd6e9..f42ebb2a5711 100644
--- a/toolchain/check/testdata/function/call/no_prelude/empty_struct.carbon
+++ b/toolchain/check/testdata/function/call/empty_struct.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/no_prelude/empty_struct.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/empty_struct.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/no_prelude/empty_struct.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/empty_struct.carbon
 
 fn Echo(a: {}) -> {} {
   return a;
diff --git a/toolchain/check/testdata/function/call/no_prelude/empty_tuple.carbon b/toolchain/check/testdata/function/call/empty_tuple.carbon
similarity index 94%
rename from toolchain/check/testdata/function/call/no_prelude/empty_tuple.carbon
rename to toolchain/check/testdata/function/call/empty_tuple.carbon
index 13fa3a030eaf..a6d5d340e692 100644
--- a/toolchain/check/testdata/function/call/no_prelude/empty_tuple.carbon
+++ b/toolchain/check/testdata/function/call/empty_tuple.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/no_prelude/empty_tuple.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/empty_tuple.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/no_prelude/empty_tuple.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/empty_tuple.carbon
 
 fn Echo(a: ()) -> () {
   return a;
diff --git a/toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon b/toolchain/check/testdata/function/call/fail_explicit_self_param.carbon
similarity index 92%
rename from toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon
rename to toolchain/check/testdata/function/call/fail_explicit_self_param.carbon
index e088a0bf7280..4e50e36de944 100644
--- a/toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon
+++ b/toolchain/check/testdata/function/call/fail_explicit_self_param.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/fail_explicit_self_param.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/no_prelude/fail_explicit_self_param.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/fail_explicit_self_param.carbon
 
 // CHECK:STDERR: fail_explicit_self_param.carbon:[[@LINE+4]]:6: error: `self` can only be declared in an implicit parameter list [SelfOutsideImplicitParamList]
 // CHECK:STDERR: fn F(self: ());
diff --git a/toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon b/toolchain/check/testdata/function/call/fail_runtime_implicit_param.carbon
similarity index 88%
rename from toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon
rename to toolchain/check/testdata/function/call/fail_runtime_implicit_param.carbon
index ce2dec2c46cc..556ef1fc42b3 100644
--- a/toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon
+++ b/toolchain/check/testdata/function/call/fail_runtime_implicit_param.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/fail_runtime_implicit_param.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/no_prelude/fail_runtime_implicit_param.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/fail_runtime_implicit_param.carbon
 
 // CHECK:STDERR: fail_runtime_implicit_param.carbon:[[@LINE+4]]:6: error: implicit parameters of functions must be constant or `self` [ImplictParamMustBeConstant]
 // CHECK:STDERR: fn F[s: ()]();
diff --git a/toolchain/check/testdata/function/call/no_prelude/params_zero.carbon b/toolchain/check/testdata/function/call/params_zero.carbon
similarity index 89%
rename from toolchain/check/testdata/function/call/no_prelude/params_zero.carbon
rename to toolchain/check/testdata/function/call/params_zero.carbon
index 9fd27d504eb8..b015d82e7624 100644
--- a/toolchain/check/testdata/function/call/no_prelude/params_zero.carbon
+++ b/toolchain/check/testdata/function/call/params_zero.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/no_prelude/params_zero.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/call/params_zero.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/no_prelude/params_zero.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/params_zero.carbon
 
 fn Foo() {}
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/export_name.carbon b/toolchain/check/testdata/function/declaration/export_name.carbon
similarity index 94%
rename from toolchain/check/testdata/function/declaration/no_prelude/export_name.carbon
rename to toolchain/check/testdata/function/declaration/export_name.carbon
index 2d85d4e40aa6..189f34c25427 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/function/declaration/export_name.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/export_name.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/export_name.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/export_name.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/export_name.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/extern.carbon b/toolchain/check/testdata/function/declaration/extern.carbon
similarity index 97%
rename from toolchain/check/testdata/function/declaration/no_prelude/extern.carbon
rename to toolchain/check/testdata/function/declaration/extern.carbon
index 02a0a2ddd152..0a59ba2735c0 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/extern.carbon
+++ b/toolchain/check/testdata/function/declaration/extern.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/extern.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/extern.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/extern.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/extern.carbon
 
 // --- basic.carbon
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon b/toolchain/check/testdata/function/declaration/extern_library.carbon
similarity index 98%
rename from toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon
rename to toolchain/check/testdata/function/declaration/extern_library.carbon
index e5b67d684ba9..3bdd562d23ce 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon
+++ b/toolchain/check/testdata/function/declaration/extern_library.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/extern_library.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/extern_library.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/extern_library.carbon
 
 // --- extern_library.carbon
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon b/toolchain/check/testdata/function/declaration/extern_library_for_default.carbon
similarity index 92%
rename from toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon
rename to toolchain/check/testdata/function/declaration/extern_library_for_default.carbon
index 5cd555903d79..cda7a5d9c236 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon
+++ b/toolchain/check/testdata/function/declaration/extern_library_for_default.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/extern_library_for_default.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/extern_library_for_default.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/extern_library_for_default.carbon
 
 // --- default.carbon
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon b/toolchain/check/testdata/function/declaration/extern_library_from_default.carbon
similarity index 92%
rename from toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon
rename to toolchain/check/testdata/function/declaration/extern_library_from_default.carbon
index dffddc825773..f3fb3a0cf980 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon
+++ b/toolchain/check/testdata/function/declaration/extern_library_from_default.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/extern_library_from_default.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/extern_library_from_default.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/extern_library_from_default.carbon
 
 // --- extern_library.carbon
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/function/declaration/fail_modifiers.carbon
similarity index 97%
rename from toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon
rename to toolchain/check/testdata/function/declaration/fail_modifiers.carbon
index 65df23658a9e..dbc85282c269 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/function/declaration/fail_modifiers.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/fail_modifiers.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/fail_modifiers.carbon
 
 // CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:9: error: `protected` must appear before `default` [ModifierMustAppearBefore]
 // CHECK:STDERR: default protected fn WrongOrder();
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon b/toolchain/check/testdata/function/declaration/fail_pattern_in_signature.carbon
similarity index 91%
rename from toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon
rename to toolchain/check/testdata/function/declaration/fail_pattern_in_signature.carbon
index 8a64ec4b085b..5a39dc46ec78 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon
+++ b/toolchain/check/testdata/function/declaration/fail_pattern_in_signature.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/fail_pattern_in_signature.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/fail_pattern_in_signature.carbon
 
 // CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+4]]:6: error: semantics TODO: `Support patterns besides bindings in parameter list` [SemanticsTodo]
 // CHECK:STDERR: fn F((a: {}, b: {}), c: {});
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon b/toolchain/check/testdata/function/declaration/fail_redecl.carbon
similarity index 97%
rename from toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon
rename to toolchain/check/testdata/function/declaration/fail_redecl.carbon
index 3c117d5847e8..eb765877fbd9 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon
+++ b/toolchain/check/testdata/function/declaration/fail_redecl.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/fail_redecl.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/fail_redecl.carbon
 
 fn A();
 // CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: error: redeclaration of `fn A` is redundant [RedeclRedundant]
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon b/toolchain/check/testdata/function/declaration/fail_todo_no_params.carbon
similarity index 96%
rename from toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon
rename to toolchain/check/testdata/function/declaration/fail_todo_no_params.carbon
index 81a0fad6503e..8c4e8cdb3a8b 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon
+++ b/toolchain/check/testdata/function/declaration/fail_todo_no_params.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/fail_todo_no_params.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_todo_no_params.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/fail_todo_no_params.carbon
 
 // --- fail_no_body.carbon
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon b/toolchain/check/testdata/function/declaration/implicit_import.carbon
similarity index 96%
rename from toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon
rename to toolchain/check/testdata/function/declaration/implicit_import.carbon
index 124b686cbf39..21022cf25094 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon
+++ b/toolchain/check/testdata/function/declaration/implicit_import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/implicit_import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/implicit_import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/implicit_import.carbon
 
 // --- basic.carbon
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon b/toolchain/check/testdata/function/declaration/name_poisoning.carbon
similarity index 97%
rename from toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon
rename to toolchain/check/testdata/function/declaration/name_poisoning.carbon
index 14e22e41f052..6abc7a7ba1df 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon
+++ b/toolchain/check/testdata/function/declaration/name_poisoning.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/name_poisoning.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/name_poisoning.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/name_poisoning.carbon
 
 // --- no_poison.carbon
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon b/toolchain/check/testdata/function/declaration/no_definition_in_impl_file.carbon
similarity index 97%
rename from toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon
rename to toolchain/check/testdata/function/declaration/no_definition_in_impl_file.carbon
index e6d941f65e91..8be262780c05 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon
+++ b/toolchain/check/testdata/function/declaration/no_definition_in_impl_file.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_definition_in_impl_file.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/no_definition_in_impl_file.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_definition_in_impl_file.carbon
 
 // --- decl_in_api_definition_in_impl.carbon
 
diff --git a/toolchain/check/testdata/function/declaration/no_prelude/simple.carbon b/toolchain/check/testdata/function/declaration/simple.carbon
similarity index 88%
rename from toolchain/check/testdata/function/declaration/no_prelude/simple.carbon
rename to toolchain/check/testdata/function/declaration/simple.carbon
index df6dd7b47dc7..06d3d9e34a84 100644
--- a/toolchain/check/testdata/function/declaration/no_prelude/simple.carbon
+++ b/toolchain/check/testdata/function/declaration/simple.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/no_prelude/simple.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/declaration/simple.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/simple.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/simple.carbon
 
 fn F();
 
diff --git a/toolchain/check/testdata/function/definition/no_prelude/basics.carbon b/toolchain/check/testdata/function/definition/basics.carbon
similarity index 91%
rename from toolchain/check/testdata/function/definition/no_prelude/basics.carbon
rename to toolchain/check/testdata/function/definition/basics.carbon
index c285bced04ce..dde1e82a8247 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/basics.carbon
+++ b/toolchain/check/testdata/function/definition/basics.carbon
@@ -4,13 +4,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/basics.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/basics.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/basics.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/basics.carbon
 
 // --- fail_incomplete_type.carbon
 
diff --git a/toolchain/check/testdata/function/definition/no_prelude/extern.carbon b/toolchain/check/testdata/function/definition/extern.carbon
similarity index 97%
rename from toolchain/check/testdata/function/definition/no_prelude/extern.carbon
rename to toolchain/check/testdata/function/definition/extern.carbon
index 130e8137c60f..0fbc53409bda 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/extern.carbon
+++ b/toolchain/check/testdata/function/definition/extern.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/extern.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/extern.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/extern.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/extern.carbon
 
 // --- extern_def.carbon
 
diff --git a/toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon b/toolchain/check/testdata/function/definition/extern_library.carbon
similarity index 98%
rename from toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon
rename to toolchain/check/testdata/function/definition/extern_library.carbon
index 003f66e511c1..6b96a175538d 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon
+++ b/toolchain/check/testdata/function/definition/extern_library.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/extern_library.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/extern_library.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/extern_library.carbon
 
 // --- one_file_extern.carbon
 
diff --git a/toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon b/toolchain/check/testdata/function/definition/fail_decl_param_mismatch.carbon
similarity index 98%
rename from toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon
rename to toolchain/check/testdata/function/definition/fail_decl_param_mismatch.carbon
index 25f283fef80a..5aa52c17259a 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon
+++ b/toolchain/check/testdata/function/definition/fail_decl_param_mismatch.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/fail_decl_param_mismatch.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/fail_decl_param_mismatch.carbon
 
 fn F();
 // CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: error: redeclaration differs because of parameter count of 1 [RedeclParamCountDiffers]
diff --git a/toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon b/toolchain/check/testdata/function/definition/fail_redef.carbon
similarity index 89%
rename from toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon
rename to toolchain/check/testdata/function/definition/fail_redef.carbon
index 7d8d31662419..900832ec08f8 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon
+++ b/toolchain/check/testdata/function/definition/fail_redef.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/fail_redef.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/fail_redef.carbon
 
 fn F() {}
 // CHECK:STDERR: fail_redef.carbon:[[@LINE+7]]:1: error: redefinition of `fn F` [RedeclRedef]
diff --git a/toolchain/check/testdata/function/definition/no_prelude/forward_decl.carbon b/toolchain/check/testdata/function/definition/forward_decl.carbon
similarity index 84%
rename from toolchain/check/testdata/function/definition/no_prelude/forward_decl.carbon
rename to toolchain/check/testdata/function/definition/forward_decl.carbon
index b2c6b682cd87..3ac680f6be3c 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/forward_decl.carbon
+++ b/toolchain/check/testdata/function/definition/forward_decl.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/forward_decl.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/forward_decl.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/forward_decl.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/forward_decl.carbon
 
 fn Foo();
 
diff --git a/toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon b/toolchain/check/testdata/function/definition/implicit_import.carbon
similarity index 98%
rename from toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon
rename to toolchain/check/testdata/function/definition/implicit_import.carbon
index b6d82550729d..66d083b2a74b 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon
+++ b/toolchain/check/testdata/function/definition/implicit_import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/implicit_import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/implicit_import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/implicit_import.carbon
 
 // --- basic.carbon
 
diff --git a/toolchain/check/testdata/function/definition/no_prelude/order.carbon b/toolchain/check/testdata/function/definition/order.carbon
similarity index 89%
rename from toolchain/check/testdata/function/definition/no_prelude/order.carbon
rename to toolchain/check/testdata/function/definition/order.carbon
index 6315bea8f73c..4d249f324954 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/order.carbon
+++ b/toolchain/check/testdata/function/definition/order.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/order.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/order.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/order.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/order.carbon
 
 fn Foo() {}
 fn Bar() {}
diff --git a/toolchain/check/testdata/function/definition/no_prelude/params_zero.carbon b/toolchain/check/testdata/function/definition/params_zero.carbon
similarity index 83%
rename from toolchain/check/testdata/function/definition/no_prelude/params_zero.carbon
rename to toolchain/check/testdata/function/definition/params_zero.carbon
index 11427d8b5584..fd10d2bf759d 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/params_zero.carbon
+++ b/toolchain/check/testdata/function/definition/params_zero.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/params_zero.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/params_zero.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/params_zero.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/params_zero.carbon
 
 fn Foo() {}
 
diff --git a/toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon b/toolchain/check/testdata/function/definition/syntactic_merge.carbon
similarity index 99%
rename from toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon
rename to toolchain/check/testdata/function/definition/syntactic_merge.carbon
index 05b9385628a9..162972150260 100644
--- a/toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon
+++ b/toolchain/check/testdata/function/definition/syntactic_merge.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/definition/syntactic_merge.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/syntactic_merge.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/syntactic_merge.carbon
 
 // --- basic.carbon
 
diff --git a/toolchain/check/testdata/function/generic/no_prelude/fail_deduce_imported_function.carbon b/toolchain/check/testdata/function/generic/fail_deduce_imported_function.carbon
similarity index 98%
rename from toolchain/check/testdata/function/generic/no_prelude/fail_deduce_imported_function.carbon
rename to toolchain/check/testdata/function/generic/fail_deduce_imported_function.carbon
index 9206fc60fc10..f5272119e332 100644
--- a/toolchain/check/testdata/function/generic/no_prelude/fail_deduce_imported_function.carbon
+++ b/toolchain/check/testdata/function/generic/fail_deduce_imported_function.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/no_prelude/fail_deduce_imported_function.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/fail_deduce_imported_function.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/no_prelude/fail_deduce_imported_function.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/fail_deduce_imported_function.carbon
 
 // --- lib.carbon
 package Lib;
diff --git a/toolchain/check/testdata/function/generic/no_prelude/forward_decl.carbon b/toolchain/check/testdata/function/generic/forward_decl.carbon
similarity index 88%
rename from toolchain/check/testdata/function/generic/no_prelude/forward_decl.carbon
rename to toolchain/check/testdata/function/generic/forward_decl.carbon
index a006e4899219..a3a359d7a047 100644
--- a/toolchain/check/testdata/function/generic/no_prelude/forward_decl.carbon
+++ b/toolchain/check/testdata/function/generic/forward_decl.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/no_prelude/forward_decl.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/forward_decl.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/no_prelude/forward_decl.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/forward_decl.carbon
 
 fn F(T:! type);
 
diff --git a/toolchain/check/testdata/function/generic/no_prelude/import_specific.carbon b/toolchain/check/testdata/function/generic/import_specific.carbon
similarity index 97%
rename from toolchain/check/testdata/function/generic/no_prelude/import_specific.carbon
rename to toolchain/check/testdata/function/generic/import_specific.carbon
index c4a794a50736..7744073a3dc0 100644
--- a/toolchain/check/testdata/function/generic/no_prelude/import_specific.carbon
+++ b/toolchain/check/testdata/function/generic/import_specific.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/no_prelude/import_specific.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/import_specific.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/no_prelude/import_specific.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/import_specific.carbon
 
 // --- library.carbon
 
diff --git a/toolchain/check/testdata/function/generic/no_prelude/indirect_generic_type.carbon b/toolchain/check/testdata/function/generic/indirect_generic_type.carbon
similarity index 95%
rename from toolchain/check/testdata/function/generic/no_prelude/indirect_generic_type.carbon
rename to toolchain/check/testdata/function/generic/indirect_generic_type.carbon
index 8e72fddbc8e0..c1710ef707dd 100644
--- a/toolchain/check/testdata/function/generic/no_prelude/indirect_generic_type.carbon
+++ b/toolchain/check/testdata/function/generic/indirect_generic_type.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/no_prelude/indirect_generic_type.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/indirect_generic_type.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/no_prelude/indirect_generic_type.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/indirect_generic_type.carbon
 
 fn F(T:! type, p: T**) -> T* {
   return *p;
diff --git a/toolchain/check/testdata/function/generic/no_prelude/template_param.carbon b/toolchain/check/testdata/function/generic/template_param.carbon
similarity index 93%
rename from toolchain/check/testdata/function/generic/no_prelude/template_param.carbon
rename to toolchain/check/testdata/function/generic/template_param.carbon
index 5b69029d358d..aa9af16c9188 100644
--- a/toolchain/check/testdata/function/generic/no_prelude/template_param.carbon
+++ b/toolchain/check/testdata/function/generic/template_param.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/no_prelude/template_param.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/template_param.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/no_prelude/template_param.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/template_param.carbon
 
 // --- fn.carbon
 
diff --git a/toolchain/check/testdata/function/generic/no_prelude/type_param_scope.carbon b/toolchain/check/testdata/function/generic/type_param_scope.carbon
similarity index 94%
rename from toolchain/check/testdata/function/generic/no_prelude/type_param_scope.carbon
rename to toolchain/check/testdata/function/generic/type_param_scope.carbon
index f0e69141aba4..b737ebf50e47 100644
--- a/toolchain/check/testdata/function/generic/no_prelude/type_param_scope.carbon
+++ b/toolchain/check/testdata/function/generic/type_param_scope.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/no_prelude/type_param_scope.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/function/generic/type_param_scope.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/no_prelude/type_param_scope.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/type_param_scope.carbon
 
 fn F(T:! type, n: T) -> T {
   let m: T = n;
diff --git a/toolchain/check/testdata/global/no_prelude/basics.carbon b/toolchain/check/testdata/global/basics.carbon
similarity index 98%
rename from toolchain/check/testdata/global/no_prelude/basics.carbon
rename to toolchain/check/testdata/global/basics.carbon
index dfcd5e0378b8..333fa3c74f32 100644
--- a/toolchain/check/testdata/global/no_prelude/basics.carbon
+++ b/toolchain/check/testdata/global/basics.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/global/no_prelude/basics.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/global/basics.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/global/no_prelude/basics.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/global/basics.carbon
 
 // --- decl.carbon
 library "[[@TEST_NAME]]";
diff --git a/toolchain/check/testdata/impl/no_prelude/basic.carbon b/toolchain/check/testdata/impl/basic.carbon
similarity index 95%
rename from toolchain/check/testdata/impl/no_prelude/basic.carbon
rename to toolchain/check/testdata/impl/basic.carbon
index a37f7adae21e..c297205e6714 100644
--- a/toolchain/check/testdata/impl/no_prelude/basic.carbon
+++ b/toolchain/check/testdata/impl/basic.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/basic.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/basic.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/basic.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/basic.carbon
 
 interface Simple {
   fn F();
diff --git a/toolchain/check/testdata/impl/no_prelude/compound.carbon b/toolchain/check/testdata/impl/compound.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/compound.carbon
rename to toolchain/check/testdata/impl/compound.carbon
index 2de884b6e354..b36d07f859a3 100644
--- a/toolchain/check/testdata/impl/no_prelude/compound.carbon
+++ b/toolchain/check/testdata/impl/compound.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/compound.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/compound.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/compound.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/compound.carbon
 
 // --- core.carbon
 package Core;
diff --git a/toolchain/check/testdata/impl/no_prelude/error_recovery.carbon b/toolchain/check/testdata/impl/error_recovery.carbon
similarity index 93%
rename from toolchain/check/testdata/impl/no_prelude/error_recovery.carbon
rename to toolchain/check/testdata/impl/error_recovery.carbon
index a2a46f8746fc..69bb68829381 100644
--- a/toolchain/check/testdata/impl/no_prelude/error_recovery.carbon
+++ b/toolchain/check/testdata/impl/error_recovery.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/error_recovery.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/error_recovery.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/error_recovery.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/error_recovery.carbon
 
 // --- fail_fuzz_crash.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/fail_alias.carbon b/toolchain/check/testdata/impl/fail_alias.carbon
similarity index 95%
rename from toolchain/check/testdata/impl/no_prelude/fail_alias.carbon
rename to toolchain/check/testdata/impl/fail_alias.carbon
index eea63f0c55d1..de9057d858d4 100644
--- a/toolchain/check/testdata/impl/no_prelude/fail_alias.carbon
+++ b/toolchain/check/testdata/impl/fail_alias.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/fail_alias.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/fail_alias.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/fail_alias.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/fail_alias.carbon
 
 interface I {}
 class C {}
diff --git a/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon b/toolchain/check/testdata/impl/fail_impl_bad_assoc_const.carbon
similarity index 93%
rename from toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon
rename to toolchain/check/testdata/impl/fail_impl_bad_assoc_const.carbon
index eaaa0a2c92f1..847fd6d9cfe4 100644
--- a/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon
+++ b/toolchain/check/testdata/impl/fail_impl_bad_assoc_const.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/fail_impl_bad_assoc_const.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/fail_impl_bad_assoc_const.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/fail_impl_bad_assoc_const.carbon
 
 interface I { let T:! type; }
 
diff --git a/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon b/toolchain/check/testdata/impl/fail_impl_bad_type.carbon
similarity index 90%
rename from toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon
rename to toolchain/check/testdata/impl/fail_impl_bad_type.carbon
index 0e046b0057b1..b60f85c2cd79 100644
--- a/toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon
+++ b/toolchain/check/testdata/impl/fail_impl_bad_type.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/fail_impl_bad_type.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/fail_impl_bad_type.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/fail_impl_bad_type.carbon
 
 interface I {}
 
diff --git a/toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon b/toolchain/check/testdata/impl/fail_undefined_interface.carbon
similarity index 98%
rename from toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon
rename to toolchain/check/testdata/impl/fail_undefined_interface.carbon
index 79e1de2852b6..c5bf0a3cf6a8 100644
--- a/toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon
+++ b/toolchain/check/testdata/impl/fail_undefined_interface.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/fail_undefined_interface.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/fail_undefined_interface.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/fail_undefined_interface.carbon
 
 // --- fail_empty_struct.carbon
 
diff --git a/toolchain/check/testdata/impl/impl_assoc_const.carbon b/toolchain/check/testdata/impl/impl_assoc_const.carbon
index 7a5c4f313bea..a057c4aea8e9 100644
--- a/toolchain/check/testdata/impl/impl_assoc_const.carbon
+++ b/toolchain/check/testdata/impl/impl_assoc_const.carbon
@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
@@ -11,394 +11,1069 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/impl_assoc_const.carbon
 
-// --- same_non_type.carbon
+// --- success.carbon
 library "[[@TEST_NAME]]";
 
-interface I {
-  let X:! {.a: bool, .b: (i32, i32)};
-}
-impl () as I where .X = {.a = true, .b = (1, 2)} and .X = {.a = not false, .b = (3 - 2, 4 / 2)} {}
+interface I { let T:! type; }
 
-// --- fail_two_different_non_type.carbon
+impl () as I where .T = {} {}
+
+// --- redecl.carbon
 library "[[@TEST_NAME]]";
 
-interface I {
-  let X:! {.a: bool, .b: (i32, i32)};
-}
-// CHECK:STDERR: fail_two_different_non_type.carbon:[[@LINE+4]]:12: error: associated constant X given two different values `{.a = true, .b = (1, 2)}` and `{.a = false, .b = (3, 4)}` [AssociatedConstantWithDifferentValues]
-// CHECK:STDERR: impl () as I where .X = {.a = true, .b = (1, 2)} and .X = {.a = false, .b = (3, 4)} {}
-// CHECK:STDERR:            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+interface I2 { let T2:! type; }
+
+impl () as I2 where .T2 = {};
+impl () as I2 where .T2 = {} {}
+
+// --- fail_redecl_adds_rewrites.carbon
+library "[[@TEST_NAME]]";
+
+interface I3 { let T3:! type; }
+
+// CHECK:STDERR: fail_redecl_adds_rewrites.carbon:[[@LINE+4]]:1: error: impl declared but not defined [ImplMissingDefinition]
+// CHECK:STDERR: impl () as I3;
+// CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
-impl () as I where .X = {.a = true, .b = (1, 2)} and .X = {.a = false, .b = (3, 4)} {}
+impl () as I3;
+impl () as I3 where .T3 = {} {}
 
-// CHECK:STDOUT: --- same_non_type.carbon
+// --- fail_mismatch.carbon
+library "[[@TEST_NAME]]";
+
+interface J { let U:! type; }
+
+// CHECK:STDERR: fail_mismatch.carbon:[[@LINE+4]]:1: error: impl declared but not defined [ImplMissingDefinition]
+// CHECK:STDERR: impl () as J where .U = {};
+// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
+impl () as J where .U = {};
+impl () as J where .U = () {}
+
+// --- fail_mismatch_bad_value.carbon
+library "[[@TEST_NAME]]";
+
+interface I4 {
+  let T4:! type;
+  let T5:! type;
+  let T6:! type;
+}
+
+// CHECK:STDERR: fail_mismatch_bad_value.carbon:[[@LINE+8]]:27: error: name `BAD1` not found [NameNotFound]
+// CHECK:STDERR: impl () as I4 where .T4 = BAD1 and .T5 = {.a: {}} and .T6 = BAD2;
+// CHECK:STDERR:                           ^~~~
+// CHECK:STDERR:
+// CHECK:STDERR: fail_mismatch_bad_value.carbon:[[@LINE+4]]:61: error: name `BAD2` not found [NameNotFound]
+// CHECK:STDERR: impl () as I4 where .T4 = BAD1 and .T5 = {.a: {}} and .T6 = BAD2;
+// CHECK:STDERR:                                                             ^~~~
+// CHECK:STDERR:
+impl () as I4 where .T4 = BAD1 and .T5 = {.a: {}} and .T6 = BAD2;
+
+// CHECK:STDERR: fail_mismatch_bad_value.carbon:[[@LINE+8]]:46: error: name `BAD3` not found [NameNotFound]
+// CHECK:STDERR: impl () as I4 where .T4 = {.b: {}} and .T5 = BAD3 and .T6 = BAD4 {}
+// CHECK:STDERR:                                              ^~~~
+// CHECK:STDERR:
+// CHECK:STDERR: fail_mismatch_bad_value.carbon:[[@LINE+4]]:61: error: name `BAD4` not found [NameNotFound]
+// CHECK:STDERR: impl () as I4 where .T4 = {.b: {}} and .T5 = BAD3 and .T6 = BAD4 {}
+// CHECK:STDERR:                                                             ^~~~
+// CHECK:STDERR:
+impl () as I4 where .T4 = {.b: {}} and .T5 = BAD3 and .T6 = BAD4 {}
+
+// --- fail_missing_on_definition.carbon
+library "[[@TEST_NAME]]";
+
+interface K { let V:! type; }
+
+impl () as K where .V = {};
+// CHECK:STDERR: fail_missing_on_definition.carbon:[[@LINE+11]]:1: error: associated constant V not given a value in impl of interface K [ImplAssociatedConstantNeedsValue]
+// CHECK:STDERR: impl () as K {}
+// CHECK:STDERR: ^~~~~~~~~~~~~~
+// CHECK:STDERR: fail_missing_on_definition.carbon:[[@LINE-6]]:19: note: associated constant declared here [AssociatedConstantHere]
+// CHECK:STDERR: interface K { let V:! type; }
+// CHECK:STDERR:                   ^~~~~~~~
+// CHECK:STDERR:
+// CHECK:STDERR: fail_missing_on_definition.carbon:[[@LINE-8]]:1: error: impl declared but not defined [ImplMissingDefinition]
+// CHECK:STDERR: impl () as K where .V = {};
+// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
+impl () as K {}
+
+// --- fail_two_different.carbon
+library "[[@TEST_NAME]]";
+
+interface L { let W:! type; }
+
+// CHECK:STDERR: fail_two_different.carbon:[[@LINE+4]]:12: error: associated constant W given two different values `()` and `{}` [AssociatedConstantWithDifferentValues]
+// CHECK:STDERR: impl () as L where .W = {} and .W = () {}
+// CHECK:STDERR:            ^~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
+impl () as L where .W = {} and .W = () {}
+
+// --- fail_two_different_first_bad.carbon
+library "[[@TEST_NAME]]";
+
+interface L2 { let W2:! type; }
+
+// CHECK:STDERR: fail_two_different_first_bad.carbon:[[@LINE+4]]:27: error: name `BAD5` not found [NameNotFound]
+// CHECK:STDERR: impl () as L2 where .W2 = BAD5 and .W2 = () {}
+// CHECK:STDERR:                           ^~~~
+// CHECK:STDERR:
+impl () as L2 where .W2 = BAD5 and .W2 = () {}
+
+// --- fail_two_different_second_bad.carbon
+library "[[@TEST_NAME]]";
+
+interface L3 { let W3:! type; }
+
+// CHECK:STDERR: fail_two_different_second_bad.carbon:[[@LINE+4]]:40: error: name `BAD6` not found [NameNotFound]
+// CHECK:STDERR: impl () as L3 where .W3 = {} and .W3 = BAD6 {}
+// CHECK:STDERR:                                        ^~~~
+// CHECK:STDERR:
+impl () as L3 where .W3 = {} and .W3 = BAD6 {}
+
+// --- fail_two_different_both_bad.carbon
+library "[[@TEST_NAME]]";
+
+interface L4 { let W4:! type; }
+
+// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+8]]:27: error: name `BAD7` not found [NameNotFound]
+// CHECK:STDERR: impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
+// CHECK:STDERR:                           ^~~~
+// CHECK:STDERR:
+// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+4]]:42: error: name `BAD8` not found [NameNotFound]
+// CHECK:STDERR: impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
+// CHECK:STDERR:                                          ^~~~
+// CHECK:STDERR:
+impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
+
+// --- repeated.carbon
+library "[[@TEST_NAME]]";
+
+interface M { let X:! type; }
+
+impl () as M where .X = {} and .X = {} {}
+
+// --- non-type.carbon
+library "[[@TEST_NAME]]";
+
+interface N {
+  let Y:! {.a: {}};
+}
+
+impl () as N where .Y = {.a = {}} { }
+
+// --- fail_where_rewrite_function.carbon
+library "[[@TEST_NAME]]";
+
+interface IF { fn F(); }
+
+class CD { }
+
+// CHECK:STDERR: fail_where_rewrite_function.carbon:[[@LINE+4]]:12: error: rewrite specified for associated function F [RewriteForAssociatedFunction]
+// CHECK:STDERR: impl CD as IF where .F = 0 {
+// CHECK:STDERR:            ^~~~~~~~~~~~~~~
+// CHECK:STDERR:
+impl CD as IF where .F = 0 {
+  fn F() {}
+}
+
+// CHECK:STDOUT: --- success.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
 // CHECK:STDOUT:   %I.type: type = facet_type <@I> [concrete]
-// CHECK:STDOUT:   %Self.826: %I.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %Bool.type: type = fn_type @Bool [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %Bool: %Bool.type = struct_value () [concrete]
-// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
-// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
-// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
-// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
-// CHECK:STDOUT:   %tuple.type.d07: type = tuple_type (%i32, %i32) [concrete]
-// CHECK:STDOUT:   %struct_type.a.b.fe2: type = struct_type {.a: bool, .b: %tuple.type.d07} [concrete]
+// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic]
 // CHECK:STDOUT:   %I.assoc_type: type = assoc_entity_type @I [concrete]
-// CHECK:STDOUT:   %assoc0.e7f: %I.assoc_type = assoc_entity element0, @I.%X [concrete]
+// CHECK:STDOUT:   %assoc0: %I.assoc_type = assoc_entity element0, @I.%T [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %.Self: %I.type = bind_symbolic_name .Self [symbolic_self]
 // CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
 // CHECK:STDOUT:   %I.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I [symbolic_self]
 // CHECK:STDOUT:   %I.facet: %I.type = facet_value %.Self.as_type, (%I.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: %struct_type.a.b.fe2 = impl_witness_access %I.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %true: bool = bool_literal true [concrete]
-// CHECK:STDOUT:   %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
-// CHECK:STDOUT:   %int_2.ecc: Core.IntLiteral = int_value 2 [concrete]
-// CHECK:STDOUT:   %tuple.type.f94: type = tuple_type (Core.IntLiteral, Core.IntLiteral) [concrete]
-// CHECK:STDOUT:   %struct_type.a.b.aa4: type = struct_type {.a: bool, .b: %tuple.type.f94} [concrete]
-// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
-// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
-// CHECK:STDOUT:   %ImplicitAs.type.205: type = facet_type <@ImplicitAs, @ImplicitAs(%i32)> [concrete]
-// CHECK:STDOUT:   %Convert.type.1b6: type = fn_type @Convert.1, @ImplicitAs(%i32) [concrete]
-// CHECK:STDOUT:   %To.c80: Core.IntLiteral = bind_symbolic_name To, 0 [symbolic]
-// CHECK:STDOUT:   %Convert.type.0f9: type = fn_type @Convert.2, @impl.4f9(%To.c80) [symbolic]
-// CHECK:STDOUT:   %Convert.f06: %Convert.type.0f9 = struct_value () [symbolic]
-// CHECK:STDOUT:   %Div.type: type = facet_type <@Div> [concrete]
-// CHECK:STDOUT:   %Sub.type: type = facet_type <@Sub> [concrete]
-// CHECK:STDOUT:   %ImplicitAs.impl_witness.c75: <witness> = impl_witness imports.%ImplicitAs.impl_witness_table.a2f, @impl.4f9(%int_32) [concrete]
-// CHECK:STDOUT:   %Convert.type.035: type = fn_type @Convert.2, @impl.4f9(%int_32) [concrete]
-// CHECK:STDOUT:   %Convert.956: %Convert.type.035 = struct_value () [concrete]
-// CHECK:STDOUT:   %ImplicitAs.facet: %ImplicitAs.type.205 = facet_value Core.IntLiteral, (%ImplicitAs.impl_witness.c75) [concrete]
-// CHECK:STDOUT:   %.9c3: type = fn_type_with_self_type %Convert.type.1b6, %ImplicitAs.facet [concrete]
-// CHECK:STDOUT:   %Convert.bound.ab5: <bound method> = bound_method %int_1.5b8, %Convert.956 [concrete]
-// CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.956, @Convert.2(%int_32) [concrete]
-// CHECK:STDOUT:   %bound_method.9a1: <bound method> = bound_method %int_1.5b8, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_1.5d2: %i32 = int_value 1 [concrete]
-// CHECK:STDOUT:   %Convert.bound.ef9: <bound method> = bound_method %int_2.ecc, %Convert.956 [concrete]
-// CHECK:STDOUT:   %bound_method.b92: <bound method> = bound_method %int_2.ecc, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_2.ef8: %i32 = int_value 2 [concrete]
-// CHECK:STDOUT:   %tuple: %tuple.type.d07 = tuple_value (%int_1.5d2, %int_2.ef8) [concrete]
-// CHECK:STDOUT:   %struct: %struct_type.a.b.fe2 = struct_value (%true, %tuple) [concrete]
-// CHECK:STDOUT:   %false: bool = bool_literal false [concrete]
-// CHECK:STDOUT:   %int_3: Core.IntLiteral = int_value 3 [concrete]
-// CHECK:STDOUT:   %Op.type.111: type = fn_type @Op.23 [concrete]
-// CHECK:STDOUT:   %Sub.impl_witness.37d: <witness> = impl_witness imports.%Sub.impl_witness_table.d7b [concrete]
-// CHECK:STDOUT:   %Sub.facet: %Sub.type = facet_value Core.IntLiteral, (%Sub.impl_witness.37d) [concrete]
-// CHECK:STDOUT:   %.07b: type = fn_type_with_self_type %Op.type.111, %Sub.facet [concrete]
-// CHECK:STDOUT:   %Op.type.2b9: type = fn_type @Op.24 [concrete]
-// CHECK:STDOUT:   %Op.667: %Op.type.2b9 = struct_value () [concrete]
-// CHECK:STDOUT:   %Op.bound.645: <bound method> = bound_method %int_3, %Op.667 [concrete]
-// CHECK:STDOUT:   %int_4: Core.IntLiteral = int_value 4 [concrete]
-// CHECK:STDOUT:   %Op.type.784: type = fn_type @Op.25 [concrete]
-// CHECK:STDOUT:   %Div.impl_witness.ec4: <witness> = impl_witness imports.%Div.impl_witness_table.381 [concrete]
-// CHECK:STDOUT:   %Div.facet: %Div.type = facet_value Core.IntLiteral, (%Div.impl_witness.ec4) [concrete]
-// CHECK:STDOUT:   %.d13: type = fn_type_with_self_type %Op.type.784, %Div.facet [concrete]
-// CHECK:STDOUT:   %Op.type.c38: type = fn_type @Op.26 [concrete]
-// CHECK:STDOUT:   %Op.553: %Op.type.c38 = struct_value () [concrete]
-// CHECK:STDOUT:   %Op.bound.2e7: <bound method> = bound_method %int_4, %Op.553 [concrete]
-// CHECK:STDOUT:   %I_where.type: type = facet_type <@I where %impl.elem0 = %struct> [concrete]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %I.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %I_where.type: type = facet_type <@I where %impl.elem0 = %empty_struct_type> [concrete]
 // CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness file.%I.impl_witness_table [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
-// CHECK:STDOUT:     .Bool = %Core.Bool
-// CHECK:STDOUT:     .Int = %Core.Int
-// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
-// CHECK:STDOUT:     .Sub = %Core.Sub
-// CHECK:STDOUT:     .Div = %Core.Div
-// CHECK:STDOUT:     import Core//prelude
-// CHECK:STDOUT:     import Core//prelude/...
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.Bool: %Bool.type = import_ref Core//prelude/types/bool, Bool, loaded [concrete = constants.%Bool]
-// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/types/int, Int, loaded [concrete = constants.%Int.generic]
-// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/operators/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
-// CHECK:STDOUT:   %Core.import_ref.a5b: @impl.4f9.%Convert.type (%Convert.type.0f9) = import_ref Core//prelude/types/int, loc19_39, loaded [symbolic = @impl.4f9.%Convert (constants.%Convert.f06)]
-// CHECK:STDOUT:   %ImplicitAs.impl_witness_table.a2f = impl_witness_table (%Core.import_ref.a5b), @impl.4f9 [concrete]
-// CHECK:STDOUT:   %Core.Sub: type = import_ref Core//prelude/operators/arithmetic, Sub, loaded [concrete = constants.%Sub.type]
-// CHECK:STDOUT:   %Core.import_ref.6c4: %Op.type.2b9 = import_ref Core//prelude/operators/arithmetic, loc98_42, loaded [concrete = constants.%Op.667]
-// CHECK:STDOUT:   %Sub.impl_witness_table.d7b = impl_witness_table (%Core.import_ref.6c4), @impl.bf8 [concrete]
-// CHECK:STDOUT:   %Core.Div: type = import_ref Core//prelude/operators/arithmetic, Div, loaded [concrete = constants.%Div.type]
-// CHECK:STDOUT:   %Core.import_ref.dfd: %Op.type.c38 = import_ref Core//prelude/operators/arithmetic, loc82_42, loaded [concrete = constants.%Op.553]
-// CHECK:STDOUT:   %Div.impl_witness_table.381 = impl_witness_table (%Core.import_ref.dfd), @impl.f0e [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .Core = imports.%Core
 // CHECK:STDOUT:     .I = %I.decl
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.import = import Core
 // CHECK:STDOUT:   %I.decl: type = interface_decl @I [concrete = constants.%I.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl.9be [concrete] {} {
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %.loc5_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc5_7.2: type = converted %.loc5_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
+// CHECK:STDOUT:     %.Self: %I.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T.ref: %I.assoc_type = name_ref T, @T.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc5_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc5_26.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc5_26.2: type = converted %.loc5_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.loc5_14: type = where_expr %.Self [concrete = constants.%I_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc5_26.2
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %I.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl [concrete]
+// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness %I.impl_witness_table [concrete = constants.%I.impl_witness]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @I {
+// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %T: type = assoc_const_decl @T [concrete] {
+// CHECK:STDOUT:     %assoc0: %I.assoc_type = assoc_entity element0, @I.%T [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .T = @T.%assoc0
+// CHECK:STDOUT:   witness = (%T)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @T(@I.%Self: %I.type) {
+// CHECK:STDOUT:   assoc_const T:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %.loc5_7.2 as %.loc5_14 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = file.%I.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T(constants.%I.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- redecl.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %I2.type: type = facet_type <@I2> [concrete]
+// CHECK:STDOUT:   %Self: %I2.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %I2.assoc_type: type = assoc_entity_type @I2 [concrete]
+// CHECK:STDOUT:   %assoc0: %I2.assoc_type = assoc_entity element0, @I2.%T2 [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %I2.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %I2.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I2 [symbolic_self]
+// CHECK:STDOUT:   %I2.facet: %I2.type = facet_value %.Self.as_type, (%I2.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %I2.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %I2_where.type: type = facet_type <@I2 where %impl.elem0 = %empty_struct_type> [concrete]
+// CHECK:STDOUT:   %I2.impl_witness: <witness> = impl_witness file.%I2.impl_witness_table [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .I2 = %I2.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %I2.decl: type = interface_decl @I2 [concrete = constants.%I2.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %.loc5_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc5_7.2: type = converted %.loc5_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %I2.ref.loc5: type = name_ref I2, file.%I2.decl [concrete = constants.%I2.type]
+// CHECK:STDOUT:     %.Self.1: %I2.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc5: %I2.type = name_ref .Self, %.Self.1 [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T2.ref.loc5: %I2.assoc_type = name_ref T2, @T2.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc5: type = facet_access_type %.Self.ref.loc5 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc5_21: type = converted %.Self.ref.loc5, %.Self.as_type.loc5 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc5: type = impl_witness_access constants.%I2.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc5_28.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc5_28.2: type = converted %.loc5_28.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.loc5_15: type = where_expr %.Self.1 [concrete = constants.%I2_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc5, %.loc5_28.2
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %I2.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl [concrete]
+// CHECK:STDOUT:   %I2.impl_witness: <witness> = impl_witness %I2.impl_witness_table [concrete = constants.%I2.impl_witness]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
 // CHECK:STDOUT:     %.loc6_7.1: %empty_tuple.type = tuple_literal ()
 // CHECK:STDOUT:     %.loc6_7.2: type = converted %.loc6_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
-// CHECK:STDOUT:     %.Self: %I.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc6_20: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %X.ref.loc6_20: %I.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0.e7f]
-// CHECK:STDOUT:     %.Self.as_type.loc6_20: type = facet_access_type %.Self.ref.loc6_20 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc6_20: type = converted %.Self.ref.loc6_20, %.Self.as_type.loc6_20 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc6_20: %struct_type.a.b.fe2 = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %true: bool = bool_literal true [concrete = constants.%true]
-// CHECK:STDOUT:     %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
-// CHECK:STDOUT:     %int_2.loc6_46: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
-// CHECK:STDOUT:     %.loc6_47.1: %tuple.type.f94 = tuple_literal (%int_1, %int_2.loc6_46)
-// CHECK:STDOUT:     %.loc6_48.1: %struct_type.a.b.aa4 = struct_literal (%true, %.loc6_47.1)
-// CHECK:STDOUT:     %impl.elem0.loc6_47.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:     %bound_method.loc6_47.1: <bound method> = bound_method %int_1, %impl.elem0.loc6_47.1 [concrete = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:     %specific_fn.loc6_47.1: <specific function> = specific_function %impl.elem0.loc6_47.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:     %bound_method.loc6_47.2: <bound method> = bound_method %int_1, %specific_fn.loc6_47.1 [concrete = constants.%bound_method.9a1]
-// CHECK:STDOUT:     %int.convert_checked.loc6_47.1: init %i32 = call %bound_method.loc6_47.2(%int_1) [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %.loc6_47.2: %i32 = value_of_initializer %int.convert_checked.loc6_47.1 [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %.loc6_47.3: %i32 = converted %int_1, %.loc6_47.2 [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %impl.elem0.loc6_47.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:     %bound_method.loc6_47.3: <bound method> = bound_method %int_2.loc6_46, %impl.elem0.loc6_47.2 [concrete = constants.%Convert.bound.ef9]
-// CHECK:STDOUT:     %specific_fn.loc6_47.2: <specific function> = specific_function %impl.elem0.loc6_47.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:     %bound_method.loc6_47.4: <bound method> = bound_method %int_2.loc6_46, %specific_fn.loc6_47.2 [concrete = constants.%bound_method.b92]
-// CHECK:STDOUT:     %int.convert_checked.loc6_47.2: init %i32 = call %bound_method.loc6_47.4(%int_2.loc6_46) [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc6_47.4: %i32 = value_of_initializer %int.convert_checked.loc6_47.2 [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc6_47.5: %i32 = converted %int_2.loc6_46, %.loc6_47.4 [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %tuple.loc6_47: %tuple.type.d07 = tuple_value (%.loc6_47.3, %.loc6_47.5) [concrete = constants.%tuple]
-// CHECK:STDOUT:     %.loc6_48.2: %tuple.type.d07 = converted %.loc6_47.1, %tuple.loc6_47 [concrete = constants.%tuple]
-// CHECK:STDOUT:     %struct.loc6_48: %struct_type.a.b.fe2 = struct_value (%true, %.loc6_48.2) [concrete = constants.%struct]
-// CHECK:STDOUT:     %.loc6_48.3: %struct_type.a.b.fe2 = converted %.loc6_48.1, %struct.loc6_48 [concrete = constants.%struct]
-// CHECK:STDOUT:     %.Self.ref.loc6_54: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %X.ref.loc6_54: %I.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0.e7f]
-// CHECK:STDOUT:     %.Self.as_type.loc6_54: type = facet_access_type %.Self.ref.loc6_54 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc6_54: type = converted %.Self.ref.loc6_54, %.Self.as_type.loc6_54 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc6_54: %struct_type.a.b.fe2 = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %false: bool = bool_literal false [concrete = constants.%false]
-// CHECK:STDOUT:     %.loc6_65: bool = not %false [concrete = constants.%true]
-// CHECK:STDOUT:     %int_3: Core.IntLiteral = int_value 3 [concrete = constants.%int_3]
-// CHECK:STDOUT:     %int_2.loc6_86: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
-// CHECK:STDOUT:     %impl.elem0.loc6_84: %.07b = impl_witness_access constants.%Sub.impl_witness.37d, element0 [concrete = constants.%Op.667]
-// CHECK:STDOUT:     %bound_method.loc6_84: <bound method> = bound_method %int_3, %impl.elem0.loc6_84 [concrete = constants.%Op.bound.645]
-// CHECK:STDOUT:     %int.ssub: init Core.IntLiteral = call %bound_method.loc6_84(%int_3, %int_2.loc6_86) [concrete = constants.%int_1.5b8]
-// CHECK:STDOUT:     %int_4: Core.IntLiteral = int_value 4 [concrete = constants.%int_4]
-// CHECK:STDOUT:     %int_2.loc6_93: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
-// CHECK:STDOUT:     %impl.elem0.loc6_91: %.d13 = impl_witness_access constants.%Div.impl_witness.ec4, element0 [concrete = constants.%Op.553]
-// CHECK:STDOUT:     %bound_method.loc6_91: <bound method> = bound_method %int_4, %impl.elem0.loc6_91 [concrete = constants.%Op.bound.2e7]
-// CHECK:STDOUT:     %int.sdiv: init Core.IntLiteral = call %bound_method.loc6_91(%int_4, %int_2.loc6_93) [concrete = constants.%int_2.ecc]
-// CHECK:STDOUT:     %.loc6_94.1: %tuple.type.f94 = tuple_literal (%int.ssub, %int.sdiv)
-// CHECK:STDOUT:     %.loc6_95.1: %struct_type.a.b.aa4 = struct_literal (%.loc6_65, %.loc6_94.1)
-// CHECK:STDOUT:     %impl.elem0.loc6_94.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:     %bound_method.loc6_94.1: <bound method> = bound_method %int.ssub, %impl.elem0.loc6_94.1 [concrete = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:     %specific_fn.loc6_94.1: <specific function> = specific_function %impl.elem0.loc6_94.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:     %bound_method.loc6_94.2: <bound method> = bound_method %int.ssub, %specific_fn.loc6_94.1 [concrete = constants.%bound_method.9a1]
-// CHECK:STDOUT:     %.loc6_84.1: Core.IntLiteral = value_of_initializer %int.ssub [concrete = constants.%int_1.5b8]
-// CHECK:STDOUT:     %.loc6_84.2: Core.IntLiteral = converted %int.ssub, %.loc6_84.1 [concrete = constants.%int_1.5b8]
-// CHECK:STDOUT:     %int.convert_checked.loc6_94.1: init %i32 = call %bound_method.loc6_94.2(%.loc6_84.2) [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %.loc6_94.2: %i32 = value_of_initializer %int.convert_checked.loc6_94.1 [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %.loc6_94.3: %i32 = converted %int.ssub, %.loc6_94.2 [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %impl.elem0.loc6_94.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:     %bound_method.loc6_94.3: <bound method> = bound_method %int.sdiv, %impl.elem0.loc6_94.2 [concrete = constants.%Convert.bound.ef9]
-// CHECK:STDOUT:     %specific_fn.loc6_94.2: <specific function> = specific_function %impl.elem0.loc6_94.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:     %bound_method.loc6_94.4: <bound method> = bound_method %int.sdiv, %specific_fn.loc6_94.2 [concrete = constants.%bound_method.b92]
-// CHECK:STDOUT:     %.loc6_91.1: Core.IntLiteral = value_of_initializer %int.sdiv [concrete = constants.%int_2.ecc]
-// CHECK:STDOUT:     %.loc6_91.2: Core.IntLiteral = converted %int.sdiv, %.loc6_91.1 [concrete = constants.%int_2.ecc]
-// CHECK:STDOUT:     %int.convert_checked.loc6_94.2: init %i32 = call %bound_method.loc6_94.4(%.loc6_91.2) [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc6_94.4: %i32 = value_of_initializer %int.convert_checked.loc6_94.2 [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc6_94.5: %i32 = converted %int.sdiv, %.loc6_94.4 [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %tuple.loc6_94: %tuple.type.d07 = tuple_value (%.loc6_94.3, %.loc6_94.5) [concrete = constants.%tuple]
-// CHECK:STDOUT:     %.loc6_95.2: %tuple.type.d07 = converted %.loc6_94.1, %tuple.loc6_94 [concrete = constants.%tuple]
-// CHECK:STDOUT:     %struct.loc6_95: %struct_type.a.b.fe2 = struct_value (%.loc6_65, %.loc6_95.2) [concrete = constants.%struct]
-// CHECK:STDOUT:     %.loc6_95.3: %struct_type.a.b.fe2 = converted %.loc6_95.1, %struct.loc6_95 [concrete = constants.%struct]
-// CHECK:STDOUT:     %.loc6_14: type = where_expr %.Self [concrete = constants.%I_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc6_20, %.loc6_48.3
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc6_54, %.loc6_95.3
+// CHECK:STDOUT:     %I2.ref.loc6: type = name_ref I2, file.%I2.decl [concrete = constants.%I2.type]
+// CHECK:STDOUT:     %.Self.2: %I2.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc6: %I2.type = name_ref .Self, %.Self.2 [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T2.ref.loc6: %I2.assoc_type = name_ref T2, @T2.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc6: type = facet_access_type %.Self.ref.loc6 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc6_21: type = converted %.Self.ref.loc6, %.Self.as_type.loc6 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc6: type = impl_witness_access constants.%I2.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc6_28.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc6_28.2: type = converted %.loc6_28.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.loc6_15: type = where_expr %.Self.2 [concrete = constants.%I2_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc6, %.loc6_28.2
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl.9be [concrete]
-// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness %I.impl_witness_table [concrete = constants.%I.impl_witness]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: %struct_type.a.b.fe2 = impl_witness_assoc_constant constants.%struct [concrete = constants.%struct]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: interface @I {
-// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self.826]
-// CHECK:STDOUT:   %X: %struct_type.a.b.fe2 = assoc_const_decl @X [concrete] {
-// CHECK:STDOUT:     %assoc0: %I.assoc_type = assoc_entity element0, @I.%X [concrete = constants.%assoc0.e7f]
+// CHECK:STDOUT: interface @I2 {
+// CHECK:STDOUT:   %Self: %I2.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %T2: type = assoc_const_decl @T2 [concrete] {
+// CHECK:STDOUT:     %assoc0: %I2.assoc_type = assoc_entity element0, @I2.%T2 [concrete = constants.%assoc0]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !members:
 // CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .X = @X.%assoc0
-// CHECK:STDOUT:   witness = (%X)
+// CHECK:STDOUT:   .T2 = @T2.%assoc0
+// CHECK:STDOUT:   witness = (%T2)
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @X(@I.%Self: %I.type) {
-// CHECK:STDOUT:   assoc_const X:! %struct_type.a.b.fe2;
+// CHECK:STDOUT: generic assoc_const @T2(@I2.%Self: %I2.type) {
+// CHECK:STDOUT:   assoc_const T2:! type;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.9be: %.loc6_7.2 as %.loc6_14 {
+// CHECK:STDOUT: impl @impl: %.loc5_7.2 as %.loc5_15 {
 // CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%I.impl_witness
+// CHECK:STDOUT:   witness = file.%I2.impl_witness
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @X(constants.%Self.826) {}
+// CHECK:STDOUT: specific @T2(constants.%Self) {}
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @X(constants.%I.facet) {}
+// CHECK:STDOUT: specific @T2(constants.%I2.facet) {}
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_two_different_non_type.carbon
+// CHECK:STDOUT: --- fail_redecl_adds_rewrites.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %I.type: type = facet_type <@I> [concrete]
-// CHECK:STDOUT:   %Self.826: %I.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %Bool.type: type = fn_type @Bool [concrete]
+// CHECK:STDOUT:   %I3.type: type = facet_type <@I3> [concrete]
+// CHECK:STDOUT:   %Self: %I3.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %I3.assoc_type: type = assoc_entity_type @I3 [concrete]
+// CHECK:STDOUT:   %assoc0: %I3.assoc_type = assoc_entity element0, @I3.%T3 [concrete]
 // CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %Bool: %Bool.type = struct_value () [concrete]
-// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
-// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
-// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
-// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
-// CHECK:STDOUT:   %tuple.type.d07: type = tuple_type (%i32, %i32) [concrete]
-// CHECK:STDOUT:   %struct_type.a.b.fe2: type = struct_type {.a: bool, .b: %tuple.type.d07} [concrete]
-// CHECK:STDOUT:   %I.assoc_type: type = assoc_entity_type @I [concrete]
-// CHECK:STDOUT:   %assoc0.e7f: %I.assoc_type = assoc_entity element0, @I.%X [concrete]
-// CHECK:STDOUT:   %.Self: %I.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %I3.impl_witness.c9d: <witness> = impl_witness file.%I3.impl_witness_table.loc9 [concrete]
+// CHECK:STDOUT:   %.Self: %I3.type = bind_symbolic_name .Self [symbolic_self]
 // CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %I.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I [symbolic_self]
-// CHECK:STDOUT:   %I.facet: %I.type = facet_value %.Self.as_type, (%I.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: %struct_type.a.b.fe2 = impl_witness_access %I.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %true: bool = bool_literal true [concrete]
-// CHECK:STDOUT:   %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
-// CHECK:STDOUT:   %int_2.ecc: Core.IntLiteral = int_value 2 [concrete]
-// CHECK:STDOUT:   %tuple.type.f94: type = tuple_type (Core.IntLiteral, Core.IntLiteral) [concrete]
-// CHECK:STDOUT:   %struct_type.a.b.aa4: type = struct_type {.a: bool, .b: %tuple.type.f94} [concrete]
-// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
-// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
-// CHECK:STDOUT:   %ImplicitAs.type.205: type = facet_type <@ImplicitAs, @ImplicitAs(%i32)> [concrete]
-// CHECK:STDOUT:   %Convert.type.1b6: type = fn_type @Convert.1, @ImplicitAs(%i32) [concrete]
-// CHECK:STDOUT:   %To.c80: Core.IntLiteral = bind_symbolic_name To, 0 [symbolic]
-// CHECK:STDOUT:   %Convert.type.0f9: type = fn_type @Convert.2, @impl.4f9(%To.c80) [symbolic]
-// CHECK:STDOUT:   %Convert.f06: %Convert.type.0f9 = struct_value () [symbolic]
-// CHECK:STDOUT:   %ImplicitAs.impl_witness.c75: <witness> = impl_witness imports.%ImplicitAs.impl_witness_table.a2f, @impl.4f9(%int_32) [concrete]
-// CHECK:STDOUT:   %Convert.type.035: type = fn_type @Convert.2, @impl.4f9(%int_32) [concrete]
-// CHECK:STDOUT:   %Convert.956: %Convert.type.035 = struct_value () [concrete]
-// CHECK:STDOUT:   %ImplicitAs.facet: %ImplicitAs.type.205 = facet_value Core.IntLiteral, (%ImplicitAs.impl_witness.c75) [concrete]
-// CHECK:STDOUT:   %.9c3: type = fn_type_with_self_type %Convert.type.1b6, %ImplicitAs.facet [concrete]
-// CHECK:STDOUT:   %Convert.bound.ab5: <bound method> = bound_method %int_1.5b8, %Convert.956 [concrete]
-// CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.956, @Convert.2(%int_32) [concrete]
-// CHECK:STDOUT:   %bound_method.9a1: <bound method> = bound_method %int_1.5b8, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_1.5d2: %i32 = int_value 1 [concrete]
-// CHECK:STDOUT:   %Convert.bound.ef9: <bound method> = bound_method %int_2.ecc, %Convert.956 [concrete]
-// CHECK:STDOUT:   %bound_method.b92: <bound method> = bound_method %int_2.ecc, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_2.ef8: %i32 = int_value 2 [concrete]
-// CHECK:STDOUT:   %tuple.21c: %tuple.type.d07 = tuple_value (%int_1.5d2, %int_2.ef8) [concrete]
-// CHECK:STDOUT:   %struct.682: %struct_type.a.b.fe2 = struct_value (%true, %tuple.21c) [concrete]
-// CHECK:STDOUT:   %false: bool = bool_literal false [concrete]
-// CHECK:STDOUT:   %int_3.1ba: Core.IntLiteral = int_value 3 [concrete]
-// CHECK:STDOUT:   %int_4.0c1: Core.IntLiteral = int_value 4 [concrete]
-// CHECK:STDOUT:   %Convert.bound.b30: <bound method> = bound_method %int_3.1ba, %Convert.956 [concrete]
-// CHECK:STDOUT:   %bound_method.047: <bound method> = bound_method %int_3.1ba, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_3.822: %i32 = int_value 3 [concrete]
-// CHECK:STDOUT:   %Convert.bound.ac3: <bound method> = bound_method %int_4.0c1, %Convert.956 [concrete]
-// CHECK:STDOUT:   %bound_method.1da: <bound method> = bound_method %int_4.0c1, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_4.940: %i32 = int_value 4 [concrete]
-// CHECK:STDOUT:   %tuple.ffd: %tuple.type.d07 = tuple_value (%int_3.822, %int_4.940) [concrete]
-// CHECK:STDOUT:   %struct.68c: %struct_type.a.b.fe2 = struct_value (%false, %tuple.ffd) [concrete]
-// CHECK:STDOUT:   %I_where.type: type = facet_type <@I where %impl.elem0 = %struct.682 and %impl.elem0 = %struct.68c> [concrete]
-// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness file.%I.impl_witness_table [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
-// CHECK:STDOUT:     .Bool = %Core.Bool
-// CHECK:STDOUT:     .Int = %Core.Int
-// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
-// CHECK:STDOUT:     import Core//prelude
-// CHECK:STDOUT:     import Core//prelude/...
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.Bool: %Bool.type = import_ref Core//prelude/types/bool, Bool, loaded [concrete = constants.%Bool]
-// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/types/int, Int, loaded [concrete = constants.%Int.generic]
-// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/operators/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
-// CHECK:STDOUT:   %Core.import_ref.a5b: @impl.4f9.%Convert.type (%Convert.type.0f9) = import_ref Core//prelude/types/int, loc19_39, loaded [symbolic = @impl.4f9.%Convert (constants.%Convert.f06)]
-// CHECK:STDOUT:   %ImplicitAs.impl_witness_table.a2f = impl_witness_table (%Core.import_ref.a5b), @impl.4f9 [concrete]
+// CHECK:STDOUT:   %I3.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I3 [symbolic_self]
+// CHECK:STDOUT:   %I3.facet: %I3.type = facet_value %.Self.as_type, (%I3.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %I3.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %I3_where.type: type = facet_type <@I3 where %impl.elem0 = %empty_struct_type> [concrete]
+// CHECK:STDOUT:   %I3.impl_witness.ea7: <witness> = impl_witness file.%I3.impl_witness_table.loc10 [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .Core = imports.%Core
-// CHECK:STDOUT:     .I = %I.decl
+// CHECK:STDOUT:     .I3 = %I3.decl
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.import = import Core
-// CHECK:STDOUT:   %I.decl: type = interface_decl @I [concrete = constants.%I.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl.dd8 [concrete] {} {
+// CHECK:STDOUT:   %I3.decl: type = interface_decl @I3 [concrete = constants.%I3.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl.b46 [concrete] {} {
+// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %I3.ref: type = name_ref I3, file.%I3.decl [concrete = constants.%I3.type]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %I3.impl_witness_table.loc9 = impl_witness_table (), @impl.b46 [concrete]
+// CHECK:STDOUT:   %I3.impl_witness.loc9: <witness> = impl_witness %I3.impl_witness_table.loc9 [concrete = constants.%I3.impl_witness.c9d]
+// CHECK:STDOUT:   impl_decl @impl.4b6 [concrete] {} {
 // CHECK:STDOUT:     %.loc10_7.1: %empty_tuple.type = tuple_literal ()
 // CHECK:STDOUT:     %.loc10_7.2: type = converted %.loc10_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
-// CHECK:STDOUT:     %.Self: %I.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc10_20: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %X.ref.loc10_20: %I.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0.e7f]
-// CHECK:STDOUT:     %.Self.as_type.loc10_20: type = facet_access_type %.Self.ref.loc10_20 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc10_20: type = converted %.Self.ref.loc10_20, %.Self.as_type.loc10_20 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc10_20: %struct_type.a.b.fe2 = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %true: bool = bool_literal true [concrete = constants.%true]
-// CHECK:STDOUT:     %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
-// CHECK:STDOUT:     %int_2: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
-// CHECK:STDOUT:     %.loc10_47.1: %tuple.type.f94 = tuple_literal (%int_1, %int_2)
-// CHECK:STDOUT:     %.loc10_48.1: %struct_type.a.b.aa4 = struct_literal (%true, %.loc10_47.1)
-// CHECK:STDOUT:     %impl.elem0.loc10_47.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:     %bound_method.loc10_47.1: <bound method> = bound_method %int_1, %impl.elem0.loc10_47.1 [concrete = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:     %specific_fn.loc10_47.1: <specific function> = specific_function %impl.elem0.loc10_47.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:     %bound_method.loc10_47.2: <bound method> = bound_method %int_1, %specific_fn.loc10_47.1 [concrete = constants.%bound_method.9a1]
-// CHECK:STDOUT:     %int.convert_checked.loc10_47.1: init %i32 = call %bound_method.loc10_47.2(%int_1) [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %.loc10_47.2: %i32 = value_of_initializer %int.convert_checked.loc10_47.1 [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %.loc10_47.3: %i32 = converted %int_1, %.loc10_47.2 [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:     %impl.elem0.loc10_47.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:     %bound_method.loc10_47.3: <bound method> = bound_method %int_2, %impl.elem0.loc10_47.2 [concrete = constants.%Convert.bound.ef9]
-// CHECK:STDOUT:     %specific_fn.loc10_47.2: <specific function> = specific_function %impl.elem0.loc10_47.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:     %bound_method.loc10_47.4: <bound method> = bound_method %int_2, %specific_fn.loc10_47.2 [concrete = constants.%bound_method.b92]
-// CHECK:STDOUT:     %int.convert_checked.loc10_47.2: init %i32 = call %bound_method.loc10_47.4(%int_2) [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc10_47.4: %i32 = value_of_initializer %int.convert_checked.loc10_47.2 [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %.loc10_47.5: %i32 = converted %int_2, %.loc10_47.4 [concrete = constants.%int_2.ef8]
-// CHECK:STDOUT:     %tuple.loc10_47: %tuple.type.d07 = tuple_value (%.loc10_47.3, %.loc10_47.5) [concrete = constants.%tuple.21c]
-// CHECK:STDOUT:     %.loc10_48.2: %tuple.type.d07 = converted %.loc10_47.1, %tuple.loc10_47 [concrete = constants.%tuple.21c]
-// CHECK:STDOUT:     %struct.loc10_48: %struct_type.a.b.fe2 = struct_value (%true, %.loc10_48.2) [concrete = constants.%struct.682]
-// CHECK:STDOUT:     %.loc10_48.3: %struct_type.a.b.fe2 = converted %.loc10_48.1, %struct.loc10_48 [concrete = constants.%struct.682]
-// CHECK:STDOUT:     %.Self.ref.loc10_54: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %X.ref.loc10_54: %I.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0.e7f]
-// CHECK:STDOUT:     %.Self.as_type.loc10_54: type = facet_access_type %.Self.ref.loc10_54 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc10_54: type = converted %.Self.ref.loc10_54, %.Self.as_type.loc10_54 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc10_54: %struct_type.a.b.fe2 = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %false: bool = bool_literal false [concrete = constants.%false]
-// CHECK:STDOUT:     %int_3: Core.IntLiteral = int_value 3 [concrete = constants.%int_3.1ba]
-// CHECK:STDOUT:     %int_4: Core.IntLiteral = int_value 4 [concrete = constants.%int_4.0c1]
-// CHECK:STDOUT:     %.loc10_82.1: %tuple.type.f94 = tuple_literal (%int_3, %int_4)
-// CHECK:STDOUT:     %.loc10_83.1: %struct_type.a.b.aa4 = struct_literal (%false, %.loc10_82.1)
-// CHECK:STDOUT:     %impl.elem0.loc10_82.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:     %bound_method.loc10_82.1: <bound method> = bound_method %int_3, %impl.elem0.loc10_82.1 [concrete = constants.%Convert.bound.b30]
-// CHECK:STDOUT:     %specific_fn.loc10_82.1: <specific function> = specific_function %impl.elem0.loc10_82.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:     %bound_method.loc10_82.2: <bound method> = bound_method %int_3, %specific_fn.loc10_82.1 [concrete = constants.%bound_method.047]
-// CHECK:STDOUT:     %int.convert_checked.loc10_82.1: init %i32 = call %bound_method.loc10_82.2(%int_3) [concrete = constants.%int_3.822]
-// CHECK:STDOUT:     %.loc10_82.2: %i32 = value_of_initializer %int.convert_checked.loc10_82.1 [concrete = constants.%int_3.822]
-// CHECK:STDOUT:     %.loc10_82.3: %i32 = converted %int_3, %.loc10_82.2 [concrete = constants.%int_3.822]
-// CHECK:STDOUT:     %impl.elem0.loc10_82.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:     %bound_method.loc10_82.3: <bound method> = bound_method %int_4, %impl.elem0.loc10_82.2 [concrete = constants.%Convert.bound.ac3]
-// CHECK:STDOUT:     %specific_fn.loc10_82.2: <specific function> = specific_function %impl.elem0.loc10_82.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:     %bound_method.loc10_82.4: <bound method> = bound_method %int_4, %specific_fn.loc10_82.2 [concrete = constants.%bound_method.1da]
-// CHECK:STDOUT:     %int.convert_checked.loc10_82.2: init %i32 = call %bound_method.loc10_82.4(%int_4) [concrete = constants.%int_4.940]
-// CHECK:STDOUT:     %.loc10_82.4: %i32 = value_of_initializer %int.convert_checked.loc10_82.2 [concrete = constants.%int_4.940]
-// CHECK:STDOUT:     %.loc10_82.5: %i32 = converted %int_4, %.loc10_82.4 [concrete = constants.%int_4.940]
-// CHECK:STDOUT:     %tuple.loc10_82: %tuple.type.d07 = tuple_value (%.loc10_82.3, %.loc10_82.5) [concrete = constants.%tuple.ffd]
-// CHECK:STDOUT:     %.loc10_83.2: %tuple.type.d07 = converted %.loc10_82.1, %tuple.loc10_82 [concrete = constants.%tuple.ffd]
-// CHECK:STDOUT:     %struct.loc10_83: %struct_type.a.b.fe2 = struct_value (%false, %.loc10_83.2) [concrete = constants.%struct.68c]
-// CHECK:STDOUT:     %.loc10_83.3: %struct_type.a.b.fe2 = converted %.loc10_83.1, %struct.loc10_83 [concrete = constants.%struct.68c]
-// CHECK:STDOUT:     %.loc10_14: type = where_expr %.Self [concrete = constants.%I_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc10_20, %.loc10_48.3
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc10_54, %.loc10_83.3
+// CHECK:STDOUT:     %I3.ref: type = name_ref I3, file.%I3.decl [concrete = constants.%I3.type]
+// CHECK:STDOUT:     %.Self: %I3.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref: %I3.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T3.ref: %I3.assoc_type = name_ref T3, @T3.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc10_21: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%I3.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc10_28.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc10_28.2: type = converted %.loc10_28.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.loc10_15: type = where_expr %.Self [concrete = constants.%I3_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc10_28.2
 // CHECK:STDOUT:     }
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I.impl_witness_table = impl_witness_table (<error>), @impl.dd8 [concrete]
-// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness %I.impl_witness_table [concrete = constants.%I.impl_witness]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: %struct_type.a.b.fe2 = impl_witness_assoc_constant constants.%struct.682 [concrete = constants.%struct.682]
+// CHECK:STDOUT:   %I3.impl_witness_table.loc10 = impl_witness_table (%impl_witness_assoc_constant), @impl.4b6 [concrete]
+// CHECK:STDOUT:   %I3.impl_witness.loc10: <witness> = impl_witness %I3.impl_witness_table.loc10 [concrete = constants.%I3.impl_witness.ea7]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: interface @I {
-// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self.826]
-// CHECK:STDOUT:   %X: %struct_type.a.b.fe2 = assoc_const_decl @X [concrete] {
-// CHECK:STDOUT:     %assoc0: %I.assoc_type = assoc_entity element0, @I.%X [concrete = constants.%assoc0.e7f]
+// CHECK:STDOUT: interface @I3 {
+// CHECK:STDOUT:   %Self: %I3.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %T3: type = assoc_const_decl @T3 [concrete] {
+// CHECK:STDOUT:     %assoc0: %I3.assoc_type = assoc_entity element0, @I3.%T3 [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .T3 = @T3.%assoc0
+// CHECK:STDOUT:   witness = (%T3)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @T3(@I3.%Self: %I3.type) {
+// CHECK:STDOUT:   assoc_const T3:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.b46: %.loc9_7.2 as %I3.ref;
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.4b6: %.loc10_7.2 as %.loc10_15 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = file.%I3.impl_witness.loc10
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T3(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T3(constants.%I3.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_mismatch.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %J.type: type = facet_type <@J> [concrete]
+// CHECK:STDOUT:   %Self: %J.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %J.assoc_type: type = assoc_entity_type @J [concrete]
+// CHECK:STDOUT:   %assoc0: %J.assoc_type = assoc_entity element0, @J.%U [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %J.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %J.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @J [symbolic_self]
+// CHECK:STDOUT:   %J.facet: %J.type = facet_value %.Self.as_type, (%J.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %J.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %J_where.type.49a: type = facet_type <@J where %impl.elem0 = %empty_struct_type> [concrete]
+// CHECK:STDOUT:   %J.impl_witness.2a1: <witness> = impl_witness file.%J.impl_witness_table.loc9 [concrete]
+// CHECK:STDOUT:   %J_where.type.344: type = facet_type <@J where %impl.elem0 = %empty_tuple.type> [concrete]
+// CHECK:STDOUT:   %J.impl_witness.006: <witness> = impl_witness file.%J.impl_witness_table.loc10 [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .J = %J.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %J.decl: type = interface_decl @J [concrete = constants.%J.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl.3df [concrete] {} {
+// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %J.ref: type = name_ref J, file.%J.decl [concrete = constants.%J.type]
+// CHECK:STDOUT:     %.Self: %J.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref: %J.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %U.ref: %J.assoc_type = name_ref U, @U.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc9_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%J.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc9_26.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc9_26.2: type = converted %.loc9_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.loc9_14: type = where_expr %.Self [concrete = constants.%J_where.type.49a] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc9_26.2
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %J.impl_witness_table.loc9 = impl_witness_table (%impl_witness_assoc_constant.loc9), @impl.3df [concrete]
+// CHECK:STDOUT:   %J.impl_witness.loc9: <witness> = impl_witness %J.impl_witness_table.loc9 [concrete = constants.%J.impl_witness.2a1]
+// CHECK:STDOUT:   %impl_witness_assoc_constant.loc9: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   impl_decl @impl.153 [concrete] {} {
+// CHECK:STDOUT:     %.loc10_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc10_7.2: type = converted %.loc10_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %J.ref: type = name_ref J, file.%J.decl [concrete = constants.%J.type]
+// CHECK:STDOUT:     %.Self: %J.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref: %J.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %U.ref: %J.assoc_type = name_ref U, @U.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc10_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%J.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc10_26.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc10_26.2: type = converted %.loc10_26.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc10_14: type = where_expr %.Self [concrete = constants.%J_where.type.344] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc10_26.2
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %J.impl_witness_table.loc10 = impl_witness_table (%impl_witness_assoc_constant.loc10), @impl.153 [concrete]
+// CHECK:STDOUT:   %J.impl_witness.loc10: <witness> = impl_witness %J.impl_witness_table.loc10 [concrete = constants.%J.impl_witness.006]
+// CHECK:STDOUT:   %impl_witness_assoc_constant.loc10: type = impl_witness_assoc_constant constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @J {
+// CHECK:STDOUT:   %Self: %J.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %U: type = assoc_const_decl @U [concrete] {
+// CHECK:STDOUT:     %assoc0: %J.assoc_type = assoc_entity element0, @J.%U [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .U = @U.%assoc0
+// CHECK:STDOUT:   witness = (%U)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @U(@J.%Self: %J.type) {
+// CHECK:STDOUT:   assoc_const U:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.3df: %.loc9_7.2 as %.loc9_14;
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.153: %.loc10_7.2 as %.loc10_14 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = file.%J.impl_witness.loc10
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @U(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @U(constants.%J.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_mismatch_bad_value.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %I4.type: type = facet_type <@I4> [concrete]
+// CHECK:STDOUT:   %Self: %I4.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %I4.assoc_type: type = assoc_entity_type @I4 [concrete]
+// CHECK:STDOUT:   %assoc0: %I4.assoc_type = assoc_entity element0, @I4.%T4 [concrete]
+// CHECK:STDOUT:   %assoc1: %I4.assoc_type = assoc_entity element1, @I4.%T5 [concrete]
+// CHECK:STDOUT:   %assoc2: %I4.assoc_type = assoc_entity element2, @I4.%T6 [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %I4.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %I4.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I4 [symbolic_self]
+// CHECK:STDOUT:   %I4.facet: %I4.type = facet_value %.Self.as_type, (%I4.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %I4.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %impl.elem1: type = impl_witness_access %I4.lookup_impl_witness, element1 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %struct_type.a: type = struct_type {.a: %empty_struct_type} [concrete]
+// CHECK:STDOUT:   %impl.elem2: type = impl_witness_access %I4.lookup_impl_witness, element2 [symbolic_self]
+// CHECK:STDOUT:   %struct_type.b: type = struct_type {.b: %empty_struct_type} [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .I4 = %I4.decl
+// CHECK:STDOUT:     .BAD1 = <poisoned>
+// CHECK:STDOUT:     .BAD2 = <poisoned>
+// CHECK:STDOUT:     .BAD3 = <poisoned>
+// CHECK:STDOUT:     .BAD4 = <poisoned>
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %I4.decl: type = interface_decl @I4 [concrete = constants.%I4.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl.de506c.1 [concrete] {} {
+// CHECK:STDOUT:     %.loc17_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc17_7.2: type = converted %.loc17_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %I4.ref: type = name_ref I4, file.%I4.decl [concrete = constants.%I4.type]
+// CHECK:STDOUT:     %.Self: %I4.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc17_21: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T4.ref: %I4.assoc_type = name_ref T4, @T4.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc17_21: type = facet_access_type %.Self.ref.loc17_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc17_21: type = converted %.Self.ref.loc17_21, %.Self.as_type.loc17_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%I4.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %BAD1.ref: <error> = name_ref BAD1, <error> [concrete = <error>]
+// CHECK:STDOUT:     %.Self.ref.loc17_36: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T5.ref: %I4.assoc_type = name_ref T5, @T5.%assoc1 [concrete = constants.%assoc1]
+// CHECK:STDOUT:     %.Self.as_type.loc17_36: type = facet_access_type %.Self.ref.loc17_36 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc17_36: type = converted %.Self.ref.loc17_36, %.Self.as_type.loc17_36 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem1: type = impl_witness_access constants.%I4.lookup_impl_witness, element1 [symbolic_self = constants.%impl.elem1]
+// CHECK:STDOUT:     %.loc17_48.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc17_48.2: type = converted %.loc17_48.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %struct_type.a: type = struct_type {.a: %empty_struct_type} [concrete = constants.%struct_type.a]
+// CHECK:STDOUT:     %.Self.ref.loc17_55: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T6.ref: %I4.assoc_type = name_ref T6, @T6.%assoc2 [concrete = constants.%assoc2]
+// CHECK:STDOUT:     %.Self.as_type.loc17_55: type = facet_access_type %.Self.ref.loc17_55 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc17_55: type = converted %.Self.ref.loc17_55, %.Self.as_type.loc17_55 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem2: type = impl_witness_access constants.%I4.lookup_impl_witness, element2 [symbolic_self = constants.%impl.elem2]
+// CHECK:STDOUT:     %BAD2.ref: <error> = name_ref BAD2, <error> [concrete = <error>]
+// CHECK:STDOUT:     %.loc17_15: type = where_expr %.Self [concrete = <error>] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, <error>
+// CHECK:STDOUT:       requirement_rewrite %impl.elem1, %struct_type.a
+// CHECK:STDOUT:       requirement_rewrite %impl.elem2, <error>
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   impl_decl @impl.de506c.2 [concrete] {} {
+// CHECK:STDOUT:     %.loc27_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc27_7.2: type = converted %.loc27_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %I4.ref: type = name_ref I4, file.%I4.decl [concrete = constants.%I4.type]
+// CHECK:STDOUT:     %.Self: %I4.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc27_21: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T4.ref: %I4.assoc_type = name_ref T4, @T4.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc27_21: type = facet_access_type %.Self.ref.loc27_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc27_21: type = converted %.Self.ref.loc27_21, %.Self.as_type.loc27_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%I4.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc27_33.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc27_33.2: type = converted %.loc27_33.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %struct_type.b: type = struct_type {.b: %empty_struct_type} [concrete = constants.%struct_type.b]
+// CHECK:STDOUT:     %.Self.ref.loc27_40: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T5.ref: %I4.assoc_type = name_ref T5, @T5.%assoc1 [concrete = constants.%assoc1]
+// CHECK:STDOUT:     %.Self.as_type.loc27_40: type = facet_access_type %.Self.ref.loc27_40 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc27_40: type = converted %.Self.ref.loc27_40, %.Self.as_type.loc27_40 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem1: type = impl_witness_access constants.%I4.lookup_impl_witness, element1 [symbolic_self = constants.%impl.elem1]
+// CHECK:STDOUT:     %BAD3.ref: <error> = name_ref BAD3, <error> [concrete = <error>]
+// CHECK:STDOUT:     %.Self.ref.loc27_55: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %T6.ref: %I4.assoc_type = name_ref T6, @T6.%assoc2 [concrete = constants.%assoc2]
+// CHECK:STDOUT:     %.Self.as_type.loc27_55: type = facet_access_type %.Self.ref.loc27_55 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc27_55: type = converted %.Self.ref.loc27_55, %.Self.as_type.loc27_55 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem2: type = impl_witness_access constants.%I4.lookup_impl_witness, element2 [symbolic_self = constants.%impl.elem2]
+// CHECK:STDOUT:     %BAD4.ref: <error> = name_ref BAD4, <error> [concrete = <error>]
+// CHECK:STDOUT:     %.loc27_15: type = where_expr %.Self [concrete = <error>] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %struct_type.b
+// CHECK:STDOUT:       requirement_rewrite %impl.elem1, <error>
+// CHECK:STDOUT:       requirement_rewrite %impl.elem2, <error>
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @I4 {
+// CHECK:STDOUT:   %Self: %I4.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %T4: type = assoc_const_decl @T4 [concrete] {
+// CHECK:STDOUT:     %assoc0: %I4.assoc_type = assoc_entity element0, @I4.%T4 [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %T5: type = assoc_const_decl @T5 [concrete] {
+// CHECK:STDOUT:     %assoc1: %I4.assoc_type = assoc_entity element1, @I4.%T5 [concrete = constants.%assoc1]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %T6: type = assoc_const_decl @T6 [concrete] {
+// CHECK:STDOUT:     %assoc2: %I4.assoc_type = assoc_entity element2, @I4.%T6 [concrete = constants.%assoc2]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .T4 = @T4.%assoc0
+// CHECK:STDOUT:   .T5 = @T5.%assoc1
+// CHECK:STDOUT:   .T6 = @T6.%assoc2
+// CHECK:STDOUT:   witness = (%T4, %T5, %T6)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @T4(@I4.%Self: %I4.type) {
+// CHECK:STDOUT:   assoc_const T4:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @T5(@I4.%Self: %I4.type) {
+// CHECK:STDOUT:   assoc_const T5:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @T6(@I4.%Self: %I4.type) {
+// CHECK:STDOUT:   assoc_const T6:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.de506c.1: %.loc17_7.2 as %.loc17_15;
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.de506c.2: %.loc27_7.2 as %.loc27_15 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = <error>
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T4(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T5(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T6(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T4(constants.%I4.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T5(constants.%I4.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @T6(constants.%I4.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_missing_on_definition.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %K.type: type = facet_type <@K> [concrete]
+// CHECK:STDOUT:   %Self: %K.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %K.assoc_type: type = assoc_entity_type @K [concrete]
+// CHECK:STDOUT:   %assoc0: %K.assoc_type = assoc_entity element0, @K.%V [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %K.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %K.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @K [symbolic_self]
+// CHECK:STDOUT:   %K.facet: %K.type = facet_value %.Self.as_type, (%K.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %K.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %K_where.type: type = facet_type <@K where %impl.elem0 = %empty_struct_type> [concrete]
+// CHECK:STDOUT:   %K.impl_witness.3ea: <witness> = impl_witness file.%K.impl_witness_table.loc5 [concrete]
+// CHECK:STDOUT:   %K.impl_witness.3f0: <witness> = impl_witness file.%K.impl_witness_table.loc17 [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .K = %K.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %K.decl: type = interface_decl @K [concrete = constants.%K.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl.16d [concrete] {} {
+// CHECK:STDOUT:     %.loc5_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc5_7.2: type = converted %.loc5_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %K.ref: type = name_ref K, file.%K.decl [concrete = constants.%K.type]
+// CHECK:STDOUT:     %.Self: %K.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref: %K.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %V.ref: %K.assoc_type = name_ref V, @V.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc5_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%K.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc5_26.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc5_26.2: type = converted %.loc5_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.loc5_14: type = where_expr %.Self [concrete = constants.%K_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc5_26.2
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %K.impl_witness_table.loc5 = impl_witness_table (%impl_witness_assoc_constant), @impl.16d [concrete]
+// CHECK:STDOUT:   %K.impl_witness.loc5: <witness> = impl_witness %K.impl_witness_table.loc5 [concrete = constants.%K.impl_witness.3ea]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   impl_decl @impl.4b0 [concrete] {} {
+// CHECK:STDOUT:     %.loc17_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc17_7.2: type = converted %.loc17_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %K.ref: type = name_ref K, file.%K.decl [concrete = constants.%K.type]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %K.impl_witness_table.loc17 = impl_witness_table (<error>), @impl.4b0 [concrete]
+// CHECK:STDOUT:   %K.impl_witness.loc17: <witness> = impl_witness %K.impl_witness_table.loc17 [concrete = constants.%K.impl_witness.3f0]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @K {
+// CHECK:STDOUT:   %Self: %K.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %V: type = assoc_const_decl @V [concrete] {
+// CHECK:STDOUT:     %assoc0: %K.assoc_type = assoc_entity element0, @K.%V [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .V = @V.%assoc0
+// CHECK:STDOUT:   witness = (%V)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @V(@K.%Self: %K.type) {
+// CHECK:STDOUT:   assoc_const V:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.16d: %.loc5_7.2 as %.loc5_14;
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.4b0: %.loc17_7.2 as %K.ref {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = file.%K.impl_witness.loc17
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @V(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @V(constants.%K.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_two_different.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %L.type: type = facet_type <@L> [concrete]
+// CHECK:STDOUT:   %Self: %L.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %L.assoc_type: type = assoc_entity_type @L [concrete]
+// CHECK:STDOUT:   %assoc0: %L.assoc_type = assoc_entity element0, @L.%W [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %L.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %L.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @L [symbolic_self]
+// CHECK:STDOUT:   %L.facet: %L.type = facet_value %.Self.as_type, (%L.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %L.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %L_where.type: type = facet_type <@L where %impl.elem0 = %empty_tuple.type and %impl.elem0 = %empty_struct_type> [concrete]
+// CHECK:STDOUT:   %L.impl_witness: <witness> = impl_witness file.%L.impl_witness_table [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .L = %L.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %L.decl: type = interface_decl @L [concrete = constants.%L.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %L.ref: type = name_ref L, file.%L.decl [concrete = constants.%L.type]
+// CHECK:STDOUT:     %.Self: %L.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc9_20: %L.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %W.ref.loc9_20: %L.assoc_type = name_ref W, @W.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc9_20: type = facet_access_type %.Self.ref.loc9_20 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc9_20: type = converted %.Self.ref.loc9_20, %.Self.as_type.loc9_20 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc9_20: type = impl_witness_access constants.%L.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc9_26.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc9_26.2: type = converted %.loc9_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.Self.ref.loc9_32: %L.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %W.ref.loc9_32: %L.assoc_type = name_ref W, @W.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc9_32: type = facet_access_type %.Self.ref.loc9_32 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc9_32: type = converted %.Self.ref.loc9_32, %.Self.as_type.loc9_32 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc9_32: type = impl_witness_access constants.%L.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc9_38.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc9_38.2: type = converted %.loc9_38.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc9_14: type = where_expr %.Self [concrete = constants.%L_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_20, %.loc9_26.2
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_32, %.loc9_38.2
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %L.impl_witness_table = impl_witness_table (<error>), @impl [concrete]
+// CHECK:STDOUT:   %L.impl_witness: <witness> = impl_witness %L.impl_witness_table [concrete = constants.%L.impl_witness]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @L {
+// CHECK:STDOUT:   %Self: %L.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %W: type = assoc_const_decl @W [concrete] {
+// CHECK:STDOUT:     %assoc0: %L.assoc_type = assoc_entity element0, @L.%W [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .W = @W.%assoc0
+// CHECK:STDOUT:   witness = (%W)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @W(@L.%Self: %L.type) {
+// CHECK:STDOUT:   assoc_const W:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %.loc9_7.2 as %.loc9_14 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = file.%L.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @W(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @W(constants.%L.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_two_different_first_bad.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %L2.type: type = facet_type <@L2> [concrete]
+// CHECK:STDOUT:   %Self: %L2.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %L2.assoc_type: type = assoc_entity_type @L2 [concrete]
+// CHECK:STDOUT:   %assoc0: %L2.assoc_type = assoc_entity element0, @L2.%W2 [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %L2.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %L2.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @L2 [symbolic_self]
+// CHECK:STDOUT:   %L2.facet: %L2.type = facet_value %.Self.as_type, (%L2.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %L2.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .L2 = %L2.decl
+// CHECK:STDOUT:     .BAD5 = <poisoned>
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %L2.decl: type = interface_decl @L2 [concrete = constants.%L2.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %L2.ref: type = name_ref L2, file.%L2.decl [concrete = constants.%L2.type]
+// CHECK:STDOUT:     %.Self: %L2.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc9_21: %L2.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %W2.ref.loc9_21: %L2.assoc_type = name_ref W2, @W2.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc9_21: type = facet_access_type %.Self.ref.loc9_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc9_21: type = converted %.Self.ref.loc9_21, %.Self.as_type.loc9_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc9_21: type = impl_witness_access constants.%L2.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %BAD5.ref: <error> = name_ref BAD5, <error> [concrete = <error>]
+// CHECK:STDOUT:     %.Self.ref.loc9_36: %L2.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %W2.ref.loc9_36: %L2.assoc_type = name_ref W2, @W2.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc9_36: type = facet_access_type %.Self.ref.loc9_36 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc9_36: type = converted %.Self.ref.loc9_36, %.Self.as_type.loc9_36 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc9_36: type = impl_witness_access constants.%L2.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc9_43.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc9_43.2: type = converted %.loc9_43.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %.loc9_15: type = where_expr %.Self [concrete = <error>] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_21, <error>
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_36, %.loc9_43.2
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @L2 {
+// CHECK:STDOUT:   %Self: %L2.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %W2: type = assoc_const_decl @W2 [concrete] {
+// CHECK:STDOUT:     %assoc0: %L2.assoc_type = assoc_entity element0, @L2.%W2 [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .W2 = @W2.%assoc0
+// CHECK:STDOUT:   witness = (%W2)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @W2(@L2.%Self: %L2.type) {
+// CHECK:STDOUT:   assoc_const W2:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %.loc9_7.2 as %.loc9_15 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = <error>
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @W2(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @W2(constants.%L2.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_two_different_second_bad.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %L3.type: type = facet_type <@L3> [concrete]
+// CHECK:STDOUT:   %Self: %L3.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %L3.assoc_type: type = assoc_entity_type @L3 [concrete]
+// CHECK:STDOUT:   %assoc0: %L3.assoc_type = assoc_entity element0, @L3.%W3 [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %L3.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %L3.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @L3 [symbolic_self]
+// CHECK:STDOUT:   %L3.facet: %L3.type = facet_value %.Self.as_type, (%L3.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %L3.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .L3 = %L3.decl
+// CHECK:STDOUT:     .BAD6 = <poisoned>
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %L3.decl: type = interface_decl @L3 [concrete = constants.%L3.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %L3.ref: type = name_ref L3, file.%L3.decl [concrete = constants.%L3.type]
+// CHECK:STDOUT:     %.Self: %L3.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc9_21: %L3.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %W3.ref.loc9_21: %L3.assoc_type = name_ref W3, @W3.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc9_21: type = facet_access_type %.Self.ref.loc9_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc9_21: type = converted %.Self.ref.loc9_21, %.Self.as_type.loc9_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc9_21: type = impl_witness_access constants.%L3.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc9_28.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc9_28.2: type = converted %.loc9_28.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.Self.ref.loc9_34: %L3.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %W3.ref.loc9_34: %L3.assoc_type = name_ref W3, @W3.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc9_34: type = facet_access_type %.Self.ref.loc9_34 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc9_34: type = converted %.Self.ref.loc9_34, %.Self.as_type.loc9_34 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc9_34: type = impl_witness_access constants.%L3.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %BAD6.ref: <error> = name_ref BAD6, <error> [concrete = <error>]
+// CHECK:STDOUT:     %.loc9_15: type = where_expr %.Self [concrete = <error>] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_21, %.loc9_28.2
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_34, <error>
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @L3 {
+// CHECK:STDOUT:   %Self: %L3.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %W3: type = assoc_const_decl @W3 [concrete] {
+// CHECK:STDOUT:     %assoc0: %L3.assoc_type = assoc_entity element0, @L3.%W3 [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .W3 = @W3.%assoc0
+// CHECK:STDOUT:   witness = (%W3)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @W3(@L3.%Self: %L3.type) {
+// CHECK:STDOUT:   assoc_const W3:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %.loc9_7.2 as %.loc9_15 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = <error>
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @W3(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @W3(constants.%L3.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_two_different_both_bad.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %L4.type: type = facet_type <@L4> [concrete]
+// CHECK:STDOUT:   %Self: %L4.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %L4.assoc_type: type = assoc_entity_type @L4 [concrete]
+// CHECK:STDOUT:   %assoc0: %L4.assoc_type = assoc_entity element0, @L4.%W4 [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %L4.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %L4.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @L4 [symbolic_self]
+// CHECK:STDOUT:   %L4.facet: %L4.type = facet_value %.Self.as_type, (%L4.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %L4.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .L4 = %L4.decl
+// CHECK:STDOUT:     .BAD7 = <poisoned>
+// CHECK:STDOUT:     .BAD8 = <poisoned>
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %L4.decl: type = interface_decl @L4 [concrete = constants.%L4.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %.loc13_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc13_7.2: type = converted %.loc13_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %L4.ref: type = name_ref L4, file.%L4.decl [concrete = constants.%L4.type]
+// CHECK:STDOUT:     %.Self: %L4.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc13_21: %L4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %W4.ref.loc13_21: %L4.assoc_type = name_ref W4, @W4.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc13_21: type = facet_access_type %.Self.ref.loc13_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc13_21: type = converted %.Self.ref.loc13_21, %.Self.as_type.loc13_21 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc13_21: type = impl_witness_access constants.%L4.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %BAD7.ref: <error> = name_ref BAD7, <error> [concrete = <error>]
+// CHECK:STDOUT:     %.Self.ref.loc13_36: %L4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %W4.ref.loc13_36: %L4.assoc_type = name_ref W4, @W4.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc13_36: type = facet_access_type %.Self.ref.loc13_36 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc13_36: type = converted %.Self.ref.loc13_36, %.Self.as_type.loc13_36 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc13_36: type = impl_witness_access constants.%L4.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %BAD8.ref: <error> = name_ref BAD8, <error> [concrete = <error>]
+// CHECK:STDOUT:     %.loc13_15: type = where_expr %.Self [concrete = <error>] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc13_21, <error>
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc13_36, <error>
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @L4 {
+// CHECK:STDOUT:   %Self: %L4.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %W4: type = assoc_const_decl @W4 [concrete] {
+// CHECK:STDOUT:     %assoc0: %L4.assoc_type = assoc_entity element0, @L4.%W4 [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .W4 = @W4.%assoc0
+// CHECK:STDOUT:   witness = (%W4)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @W4(@L4.%Self: %L4.type) {
+// CHECK:STDOUT:   assoc_const W4:! type;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %.loc13_7.2 as %.loc13_15 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = <error>
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @W4(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @W4(constants.%L4.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- repeated.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %M.type: type = facet_type <@M> [concrete]
+// CHECK:STDOUT:   %Self: %M.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %M.assoc_type: type = assoc_entity_type @M [concrete]
+// CHECK:STDOUT:   %assoc0: %M.assoc_type = assoc_entity element0, @M.%X [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %.Self: %M.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %M.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @M [symbolic_self]
+// CHECK:STDOUT:   %M.facet: %M.type = facet_value %.Self.as_type, (%M.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %M.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %M_where.type: type = facet_type <@M where %impl.elem0 = %empty_struct_type> [concrete]
+// CHECK:STDOUT:   %M.impl_witness: <witness> = impl_witness file.%M.impl_witness_table [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .M = %M.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %M.decl: type = interface_decl @M [concrete = constants.%M.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %.loc5_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc5_7.2: type = converted %.loc5_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %M.ref: type = name_ref M, file.%M.decl [concrete = constants.%M.type]
+// CHECK:STDOUT:     %.Self: %M.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc5_20: %M.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %X.ref.loc5_20: %M.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc5_20: type = facet_access_type %.Self.ref.loc5_20 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc5_20: type = converted %.Self.ref.loc5_20, %.Self.as_type.loc5_20 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc5_20: type = impl_witness_access constants.%M.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc5_26.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc5_26.2: type = converted %.loc5_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.Self.ref.loc5_32: %M.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %X.ref.loc5_32: %M.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type.loc5_32: type = facet_access_type %.Self.ref.loc5_32 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc5_32: type = converted %.Self.ref.loc5_32, %.Self.as_type.loc5_32 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc5_32: type = impl_witness_access constants.%M.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc5_38.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc5_38.2: type = converted %.loc5_38.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:     %.loc5_14: type = where_expr %.Self [concrete = constants.%M_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc5_20, %.loc5_26.2
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc5_32, %.loc5_38.2
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %M.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl [concrete]
+// CHECK:STDOUT:   %M.impl_witness: <witness> = impl_witness %M.impl_witness_table [concrete = constants.%M.impl_witness]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @M {
+// CHECK:STDOUT:   %Self: %M.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %X: type = assoc_const_decl @X [concrete] {
+// CHECK:STDOUT:     %assoc0: %M.assoc_type = assoc_entity element0, @M.%X [concrete = constants.%assoc0]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !members:
@@ -407,16 +1082,184 @@ impl () as I where .X = {.a = true, .b = (1, 2)} and .X = {.a = false, .b = (3,
 // CHECK:STDOUT:   witness = (%X)
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @X(@I.%Self: %I.type) {
-// CHECK:STDOUT:   assoc_const X:! %struct_type.a.b.fe2;
+// CHECK:STDOUT: generic assoc_const @X(@M.%Self: %M.type) {
+// CHECK:STDOUT:   assoc_const X:! type;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.dd8: %.loc10_7.2 as %.loc10_14 {
+// CHECK:STDOUT: impl @impl: %.loc5_7.2 as %.loc5_14 {
 // CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%I.impl_witness
+// CHECK:STDOUT:   witness = file.%M.impl_witness
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @X(constants.%Self.826) {}
+// CHECK:STDOUT: specific @X(constants.%Self) {}
 // CHECK:STDOUT:
-// CHECK:STDOUT: specific @X(constants.%I.facet) {}
+// CHECK:STDOUT: specific @X(constants.%M.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- non-type.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %N.type: type = facet_type <@N> [concrete]
+// CHECK:STDOUT:   %Self: %N.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %struct_type.a.225: type = struct_type {.a: %empty_struct_type} [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %N.assoc_type: type = assoc_entity_type @N [concrete]
+// CHECK:STDOUT:   %assoc0: %N.assoc_type = assoc_entity element0, @N.%Y [concrete]
+// CHECK:STDOUT:   %.Self: %N.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %N.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @N [symbolic_self]
+// CHECK:STDOUT:   %N.facet: %N.type = facet_value %.Self.as_type, (%N.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: %struct_type.a.225 = impl_witness_access %N.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %empty_struct: %empty_struct_type = struct_value () [concrete]
+// CHECK:STDOUT:   %struct: %struct_type.a.225 = struct_value (%empty_struct) [concrete]
+// CHECK:STDOUT:   %N_where.type: type = facet_type <@N where %impl.elem0 = %struct> [concrete]
+// CHECK:STDOUT:   %N.impl_witness: <witness> = impl_witness file.%N.impl_witness_table [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .N = %N.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %N.decl: type = interface_decl @N [concrete = constants.%N.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %.loc7_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc7_7.2: type = converted %.loc7_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %N.ref: type = name_ref N, file.%N.decl [concrete = constants.%N.type]
+// CHECK:STDOUT:     %.Self: %N.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref: %N.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %Y.ref: %N.assoc_type = name_ref Y, @Y.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc7_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: %struct_type.a.225 = impl_witness_access constants.%N.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %.loc7_32: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:     %.loc7_33.1: %struct_type.a.225 = struct_literal (%.loc7_32)
+// CHECK:STDOUT:     %empty_struct: %empty_struct_type = struct_value () [concrete = constants.%empty_struct]
+// CHECK:STDOUT:     %.loc7_33.2: %empty_struct_type = converted %.loc7_32, %empty_struct [concrete = constants.%empty_struct]
+// CHECK:STDOUT:     %struct: %struct_type.a.225 = struct_value (%.loc7_33.2) [concrete = constants.%struct]
+// CHECK:STDOUT:     %.loc7_33.3: %struct_type.a.225 = converted %.loc7_33.1, %struct [concrete = constants.%struct]
+// CHECK:STDOUT:     %.loc7_14: type = where_expr %.Self [concrete = constants.%N_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc7_33.3
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %N.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl [concrete]
+// CHECK:STDOUT:   %N.impl_witness: <witness> = impl_witness %N.impl_witness_table [concrete = constants.%N.impl_witness]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: %struct_type.a.225 = impl_witness_assoc_constant constants.%struct [concrete = constants.%struct]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @N {
+// CHECK:STDOUT:   %Self: %N.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %Y: %struct_type.a.225 = assoc_const_decl @Y [concrete] {
+// CHECK:STDOUT:     %assoc0: %N.assoc_type = assoc_entity element0, @N.%Y [concrete = constants.%assoc0]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .Y = @Y.%assoc0
+// CHECK:STDOUT:   witness = (%Y)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @Y(@N.%Self: %N.type) {
+// CHECK:STDOUT:   assoc_const Y:! %struct_type.a.225;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %.loc7_7.2 as %.loc7_14 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = file.%N.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @Y(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @Y(constants.%N.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_where_rewrite_function.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %IF.type: type = facet_type <@IF> [concrete]
+// CHECK:STDOUT:   %Self: %IF.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %F.type.496: type = fn_type @F.1 [concrete]
+// CHECK:STDOUT:   %F.1de: %F.type.496 = struct_value () [concrete]
+// CHECK:STDOUT:   %IF.assoc_type: type = assoc_entity_type @IF [concrete]
+// CHECK:STDOUT:   %assoc0: %IF.assoc_type = assoc_entity element0, @IF.%F.decl [concrete]
+// CHECK:STDOUT:   %CD: type = class_type @CD [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
+// CHECK:STDOUT:   %.Self: %IF.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %IF.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @IF [symbolic_self]
+// CHECK:STDOUT:   %IF.facet.01b: %IF.type = facet_value %.Self.as_type, (%IF.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %.c5b: type = fn_type_with_self_type %F.type.496, %IF.facet.01b [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: %.c5b = impl_witness_access %IF.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
+// CHECK:STDOUT:   %IF_where.type: type = facet_type <@IF where %impl.elem0 = %int_0> [concrete]
+// CHECK:STDOUT:   %IF.impl_witness: <witness> = impl_witness file.%IF.impl_witness_table [concrete]
+// CHECK:STDOUT:   %F.type.f56: type = fn_type @F.2 [concrete]
+// CHECK:STDOUT:   %F.fae: %F.type.f56 = struct_value () [concrete]
+// CHECK:STDOUT:   %IF.facet.60c: %IF.type = facet_value %CD, (%IF.impl_witness) [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .IF = %IF.decl
+// CHECK:STDOUT:     .CD = %CD.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %IF.decl: type = interface_decl @IF [concrete = constants.%IF.type] {} {}
+// CHECK:STDOUT:   %CD.decl: type = class_decl @CD [concrete = constants.%CD] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %CD.ref: type = name_ref CD, file.%CD.decl [concrete = constants.%CD]
+// CHECK:STDOUT:     %IF.ref: type = name_ref IF, file.%IF.decl [concrete = constants.%IF.type]
+// CHECK:STDOUT:     %.Self: %IF.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref: %IF.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %F.ref: %IF.assoc_type = name_ref F, @IF.%assoc0 [concrete = constants.%assoc0]
+// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc11_21: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0: %.c5b = impl_witness_access constants.%IF.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
+// CHECK:STDOUT:     %.loc11_15: type = where_expr %.Self [concrete = constants.%IF_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %int_0
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %IF.impl_witness_table = impl_witness_table (@impl.%F.decl), @impl [concrete]
+// CHECK:STDOUT:   %IF.impl_witness: <witness> = impl_witness %IF.impl_witness_table [concrete = constants.%IF.impl_witness]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @IF {
+// CHECK:STDOUT:   %Self: %IF.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
+// CHECK:STDOUT:   %F.decl: %F.type.496 = fn_decl @F.1 [concrete = constants.%F.1de] {} {}
+// CHECK:STDOUT:   %assoc0: %IF.assoc_type = assoc_entity element0, %F.decl [concrete = constants.%assoc0]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .F = %assoc0
+// CHECK:STDOUT:   witness = (%F.decl)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %CD.ref as %.loc11_15 {
+// CHECK:STDOUT:   %F.decl: %F.type.f56 = fn_decl @F.2 [concrete = constants.%F.fae] {} {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .F = %F.decl
+// CHECK:STDOUT:   witness = file.%IF.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @CD {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%CD
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic fn @F.1(@IF.%Self: %IF.type) {
+// CHECK:STDOUT:   fn();
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @F.2() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F.1(constants.%Self) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @F.1(constants.%IF.facet.60c) {}
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/impl_assoc_const_with_prelude.carbon b/toolchain/check/testdata/impl/impl_assoc_const_with_prelude.carbon
new file mode 100644
index 000000000000..edc765c55035
--- /dev/null
+++ b/toolchain/check/testdata/impl/impl_assoc_const_with_prelude.carbon
@@ -0,0 +1,422 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
+// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/impl_assoc_const_with_prelude.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/impl_assoc_const_with_prelude.carbon
+
+// --- same_non_type.carbon
+library "[[@TEST_NAME]]";
+
+interface I {
+  let X:! {.a: bool, .b: (i32, i32)};
+}
+impl () as I where .X = {.a = true, .b = (1, 2)} and .X = {.a = not false, .b = (3 - 2, 4 / 2)} {}
+
+// --- fail_two_different_non_type.carbon
+library "[[@TEST_NAME]]";
+
+interface I {
+  let X:! {.a: bool, .b: (i32, i32)};
+}
+// CHECK:STDERR: fail_two_different_non_type.carbon:[[@LINE+4]]:12: error: associated constant X given two different values `{.a = true, .b = (1, 2)}` and `{.a = false, .b = (3, 4)}` [AssociatedConstantWithDifferentValues]
+// CHECK:STDERR: impl () as I where .X = {.a = true, .b = (1, 2)} and .X = {.a = false, .b = (3, 4)} {}
+// CHECK:STDERR:            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// CHECK:STDERR:
+impl () as I where .X = {.a = true, .b = (1, 2)} and .X = {.a = false, .b = (3, 4)} {}
+
+// CHECK:STDOUT: --- same_non_type.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %I.type: type = facet_type <@I> [concrete]
+// CHECK:STDOUT:   %Self.826: %I.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %Bool.type: type = fn_type @Bool [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %Bool: %Bool.type = struct_value () [concrete]
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
+// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
+// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
+// CHECK:STDOUT:   %tuple.type.d07: type = tuple_type (%i32, %i32) [concrete]
+// CHECK:STDOUT:   %struct_type.a.b.fe2: type = struct_type {.a: bool, .b: %tuple.type.d07} [concrete]
+// CHECK:STDOUT:   %I.assoc_type: type = assoc_entity_type @I [concrete]
+// CHECK:STDOUT:   %assoc0.e7f: %I.assoc_type = assoc_entity element0, @I.%X [concrete]
+// CHECK:STDOUT:   %.Self: %I.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %I.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I [symbolic_self]
+// CHECK:STDOUT:   %I.facet: %I.type = facet_value %.Self.as_type, (%I.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: %struct_type.a.b.fe2 = impl_witness_access %I.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %true: bool = bool_literal true [concrete]
+// CHECK:STDOUT:   %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
+// CHECK:STDOUT:   %int_2.ecc: Core.IntLiteral = int_value 2 [concrete]
+// CHECK:STDOUT:   %tuple.type.f94: type = tuple_type (Core.IntLiteral, Core.IntLiteral) [concrete]
+// CHECK:STDOUT:   %struct_type.a.b.aa4: type = struct_type {.a: bool, .b: %tuple.type.f94} [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
+// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.205: type = facet_type <@ImplicitAs, @ImplicitAs(%i32)> [concrete]
+// CHECK:STDOUT:   %Convert.type.1b6: type = fn_type @Convert.1, @ImplicitAs(%i32) [concrete]
+// CHECK:STDOUT:   %To.c80: Core.IntLiteral = bind_symbolic_name To, 0 [symbolic]
+// CHECK:STDOUT:   %Convert.type.0f9: type = fn_type @Convert.2, @impl.4f9(%To.c80) [symbolic]
+// CHECK:STDOUT:   %Convert.f06: %Convert.type.0f9 = struct_value () [symbolic]
+// CHECK:STDOUT:   %Div.type: type = facet_type <@Div> [concrete]
+// CHECK:STDOUT:   %Sub.type: type = facet_type <@Sub> [concrete]
+// CHECK:STDOUT:   %ImplicitAs.impl_witness.c75: <witness> = impl_witness imports.%ImplicitAs.impl_witness_table.a2f, @impl.4f9(%int_32) [concrete]
+// CHECK:STDOUT:   %Convert.type.035: type = fn_type @Convert.2, @impl.4f9(%int_32) [concrete]
+// CHECK:STDOUT:   %Convert.956: %Convert.type.035 = struct_value () [concrete]
+// CHECK:STDOUT:   %ImplicitAs.facet: %ImplicitAs.type.205 = facet_value Core.IntLiteral, (%ImplicitAs.impl_witness.c75) [concrete]
+// CHECK:STDOUT:   %.9c3: type = fn_type_with_self_type %Convert.type.1b6, %ImplicitAs.facet [concrete]
+// CHECK:STDOUT:   %Convert.bound.ab5: <bound method> = bound_method %int_1.5b8, %Convert.956 [concrete]
+// CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.956, @Convert.2(%int_32) [concrete]
+// CHECK:STDOUT:   %bound_method.9a1: <bound method> = bound_method %int_1.5b8, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_1.5d2: %i32 = int_value 1 [concrete]
+// CHECK:STDOUT:   %Convert.bound.ef9: <bound method> = bound_method %int_2.ecc, %Convert.956 [concrete]
+// CHECK:STDOUT:   %bound_method.b92: <bound method> = bound_method %int_2.ecc, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_2.ef8: %i32 = int_value 2 [concrete]
+// CHECK:STDOUT:   %tuple: %tuple.type.d07 = tuple_value (%int_1.5d2, %int_2.ef8) [concrete]
+// CHECK:STDOUT:   %struct: %struct_type.a.b.fe2 = struct_value (%true, %tuple) [concrete]
+// CHECK:STDOUT:   %false: bool = bool_literal false [concrete]
+// CHECK:STDOUT:   %int_3: Core.IntLiteral = int_value 3 [concrete]
+// CHECK:STDOUT:   %Op.type.111: type = fn_type @Op.23 [concrete]
+// CHECK:STDOUT:   %Sub.impl_witness.37d: <witness> = impl_witness imports.%Sub.impl_witness_table.d7b [concrete]
+// CHECK:STDOUT:   %Sub.facet: %Sub.type = facet_value Core.IntLiteral, (%Sub.impl_witness.37d) [concrete]
+// CHECK:STDOUT:   %.07b: type = fn_type_with_self_type %Op.type.111, %Sub.facet [concrete]
+// CHECK:STDOUT:   %Op.type.2b9: type = fn_type @Op.24 [concrete]
+// CHECK:STDOUT:   %Op.667: %Op.type.2b9 = struct_value () [concrete]
+// CHECK:STDOUT:   %Op.bound.645: <bound method> = bound_method %int_3, %Op.667 [concrete]
+// CHECK:STDOUT:   %int_4: Core.IntLiteral = int_value 4 [concrete]
+// CHECK:STDOUT:   %Op.type.784: type = fn_type @Op.25 [concrete]
+// CHECK:STDOUT:   %Div.impl_witness.ec4: <witness> = impl_witness imports.%Div.impl_witness_table.381 [concrete]
+// CHECK:STDOUT:   %Div.facet: %Div.type = facet_value Core.IntLiteral, (%Div.impl_witness.ec4) [concrete]
+// CHECK:STDOUT:   %.d13: type = fn_type_with_self_type %Op.type.784, %Div.facet [concrete]
+// CHECK:STDOUT:   %Op.type.c38: type = fn_type @Op.26 [concrete]
+// CHECK:STDOUT:   %Op.553: %Op.type.c38 = struct_value () [concrete]
+// CHECK:STDOUT:   %Op.bound.2e7: <bound method> = bound_method %int_4, %Op.553 [concrete]
+// CHECK:STDOUT:   %I_where.type: type = facet_type <@I where %impl.elem0 = %struct> [concrete]
+// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness file.%I.impl_witness_table [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .Bool = %Core.Bool
+// CHECK:STDOUT:     .Int = %Core.Int
+// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
+// CHECK:STDOUT:     .Sub = %Core.Sub
+// CHECK:STDOUT:     .Div = %Core.Div
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.Bool: %Bool.type = import_ref Core//prelude/types/bool, Bool, loaded [concrete = constants.%Bool]
+// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/types/int, Int, loaded [concrete = constants.%Int.generic]
+// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/operators/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
+// CHECK:STDOUT:   %Core.import_ref.a5b: @impl.4f9.%Convert.type (%Convert.type.0f9) = import_ref Core//prelude/types/int, loc19_39, loaded [symbolic = @impl.4f9.%Convert (constants.%Convert.f06)]
+// CHECK:STDOUT:   %ImplicitAs.impl_witness_table.a2f = impl_witness_table (%Core.import_ref.a5b), @impl.4f9 [concrete]
+// CHECK:STDOUT:   %Core.Sub: type = import_ref Core//prelude/operators/arithmetic, Sub, loaded [concrete = constants.%Sub.type]
+// CHECK:STDOUT:   %Core.import_ref.6c4: %Op.type.2b9 = import_ref Core//prelude/operators/arithmetic, loc98_42, loaded [concrete = constants.%Op.667]
+// CHECK:STDOUT:   %Sub.impl_witness_table.d7b = impl_witness_table (%Core.import_ref.6c4), @impl.bf8 [concrete]
+// CHECK:STDOUT:   %Core.Div: type = import_ref Core//prelude/operators/arithmetic, Div, loaded [concrete = constants.%Div.type]
+// CHECK:STDOUT:   %Core.import_ref.dfd: %Op.type.c38 = import_ref Core//prelude/operators/arithmetic, loc82_42, loaded [concrete = constants.%Op.553]
+// CHECK:STDOUT:   %Div.impl_witness_table.381 = impl_witness_table (%Core.import_ref.dfd), @impl.f0e [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .I = %I.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %I.decl: type = interface_decl @I [concrete = constants.%I.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl.9be [concrete] {} {
+// CHECK:STDOUT:     %.loc6_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc6_7.2: type = converted %.loc6_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
+// CHECK:STDOUT:     %.Self: %I.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc6_20: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %X.ref.loc6_20: %I.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0.e7f]
+// CHECK:STDOUT:     %.Self.as_type.loc6_20: type = facet_access_type %.Self.ref.loc6_20 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc6_20: type = converted %.Self.ref.loc6_20, %.Self.as_type.loc6_20 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc6_20: %struct_type.a.b.fe2 = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %true: bool = bool_literal true [concrete = constants.%true]
+// CHECK:STDOUT:     %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
+// CHECK:STDOUT:     %int_2.loc6_46: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
+// CHECK:STDOUT:     %.loc6_47.1: %tuple.type.f94 = tuple_literal (%int_1, %int_2.loc6_46)
+// CHECK:STDOUT:     %.loc6_48.1: %struct_type.a.b.aa4 = struct_literal (%true, %.loc6_47.1)
+// CHECK:STDOUT:     %impl.elem0.loc6_47.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:     %bound_method.loc6_47.1: <bound method> = bound_method %int_1, %impl.elem0.loc6_47.1 [concrete = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:     %specific_fn.loc6_47.1: <specific function> = specific_function %impl.elem0.loc6_47.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:     %bound_method.loc6_47.2: <bound method> = bound_method %int_1, %specific_fn.loc6_47.1 [concrete = constants.%bound_method.9a1]
+// CHECK:STDOUT:     %int.convert_checked.loc6_47.1: init %i32 = call %bound_method.loc6_47.2(%int_1) [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %.loc6_47.2: %i32 = value_of_initializer %int.convert_checked.loc6_47.1 [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %.loc6_47.3: %i32 = converted %int_1, %.loc6_47.2 [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %impl.elem0.loc6_47.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:     %bound_method.loc6_47.3: <bound method> = bound_method %int_2.loc6_46, %impl.elem0.loc6_47.2 [concrete = constants.%Convert.bound.ef9]
+// CHECK:STDOUT:     %specific_fn.loc6_47.2: <specific function> = specific_function %impl.elem0.loc6_47.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:     %bound_method.loc6_47.4: <bound method> = bound_method %int_2.loc6_46, %specific_fn.loc6_47.2 [concrete = constants.%bound_method.b92]
+// CHECK:STDOUT:     %int.convert_checked.loc6_47.2: init %i32 = call %bound_method.loc6_47.4(%int_2.loc6_46) [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %.loc6_47.4: %i32 = value_of_initializer %int.convert_checked.loc6_47.2 [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %.loc6_47.5: %i32 = converted %int_2.loc6_46, %.loc6_47.4 [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %tuple.loc6_47: %tuple.type.d07 = tuple_value (%.loc6_47.3, %.loc6_47.5) [concrete = constants.%tuple]
+// CHECK:STDOUT:     %.loc6_48.2: %tuple.type.d07 = converted %.loc6_47.1, %tuple.loc6_47 [concrete = constants.%tuple]
+// CHECK:STDOUT:     %struct.loc6_48: %struct_type.a.b.fe2 = struct_value (%true, %.loc6_48.2) [concrete = constants.%struct]
+// CHECK:STDOUT:     %.loc6_48.3: %struct_type.a.b.fe2 = converted %.loc6_48.1, %struct.loc6_48 [concrete = constants.%struct]
+// CHECK:STDOUT:     %.Self.ref.loc6_54: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %X.ref.loc6_54: %I.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0.e7f]
+// CHECK:STDOUT:     %.Self.as_type.loc6_54: type = facet_access_type %.Self.ref.loc6_54 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc6_54: type = converted %.Self.ref.loc6_54, %.Self.as_type.loc6_54 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc6_54: %struct_type.a.b.fe2 = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %false: bool = bool_literal false [concrete = constants.%false]
+// CHECK:STDOUT:     %.loc6_65: bool = not %false [concrete = constants.%true]
+// CHECK:STDOUT:     %int_3: Core.IntLiteral = int_value 3 [concrete = constants.%int_3]
+// CHECK:STDOUT:     %int_2.loc6_86: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
+// CHECK:STDOUT:     %impl.elem0.loc6_84: %.07b = impl_witness_access constants.%Sub.impl_witness.37d, element0 [concrete = constants.%Op.667]
+// CHECK:STDOUT:     %bound_method.loc6_84: <bound method> = bound_method %int_3, %impl.elem0.loc6_84 [concrete = constants.%Op.bound.645]
+// CHECK:STDOUT:     %int.ssub: init Core.IntLiteral = call %bound_method.loc6_84(%int_3, %int_2.loc6_86) [concrete = constants.%int_1.5b8]
+// CHECK:STDOUT:     %int_4: Core.IntLiteral = int_value 4 [concrete = constants.%int_4]
+// CHECK:STDOUT:     %int_2.loc6_93: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
+// CHECK:STDOUT:     %impl.elem0.loc6_91: %.d13 = impl_witness_access constants.%Div.impl_witness.ec4, element0 [concrete = constants.%Op.553]
+// CHECK:STDOUT:     %bound_method.loc6_91: <bound method> = bound_method %int_4, %impl.elem0.loc6_91 [concrete = constants.%Op.bound.2e7]
+// CHECK:STDOUT:     %int.sdiv: init Core.IntLiteral = call %bound_method.loc6_91(%int_4, %int_2.loc6_93) [concrete = constants.%int_2.ecc]
+// CHECK:STDOUT:     %.loc6_94.1: %tuple.type.f94 = tuple_literal (%int.ssub, %int.sdiv)
+// CHECK:STDOUT:     %.loc6_95.1: %struct_type.a.b.aa4 = struct_literal (%.loc6_65, %.loc6_94.1)
+// CHECK:STDOUT:     %impl.elem0.loc6_94.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:     %bound_method.loc6_94.1: <bound method> = bound_method %int.ssub, %impl.elem0.loc6_94.1 [concrete = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:     %specific_fn.loc6_94.1: <specific function> = specific_function %impl.elem0.loc6_94.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:     %bound_method.loc6_94.2: <bound method> = bound_method %int.ssub, %specific_fn.loc6_94.1 [concrete = constants.%bound_method.9a1]
+// CHECK:STDOUT:     %.loc6_84.1: Core.IntLiteral = value_of_initializer %int.ssub [concrete = constants.%int_1.5b8]
+// CHECK:STDOUT:     %.loc6_84.2: Core.IntLiteral = converted %int.ssub, %.loc6_84.1 [concrete = constants.%int_1.5b8]
+// CHECK:STDOUT:     %int.convert_checked.loc6_94.1: init %i32 = call %bound_method.loc6_94.2(%.loc6_84.2) [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %.loc6_94.2: %i32 = value_of_initializer %int.convert_checked.loc6_94.1 [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %.loc6_94.3: %i32 = converted %int.ssub, %.loc6_94.2 [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %impl.elem0.loc6_94.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:     %bound_method.loc6_94.3: <bound method> = bound_method %int.sdiv, %impl.elem0.loc6_94.2 [concrete = constants.%Convert.bound.ef9]
+// CHECK:STDOUT:     %specific_fn.loc6_94.2: <specific function> = specific_function %impl.elem0.loc6_94.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:     %bound_method.loc6_94.4: <bound method> = bound_method %int.sdiv, %specific_fn.loc6_94.2 [concrete = constants.%bound_method.b92]
+// CHECK:STDOUT:     %.loc6_91.1: Core.IntLiteral = value_of_initializer %int.sdiv [concrete = constants.%int_2.ecc]
+// CHECK:STDOUT:     %.loc6_91.2: Core.IntLiteral = converted %int.sdiv, %.loc6_91.1 [concrete = constants.%int_2.ecc]
+// CHECK:STDOUT:     %int.convert_checked.loc6_94.2: init %i32 = call %bound_method.loc6_94.4(%.loc6_91.2) [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %.loc6_94.4: %i32 = value_of_initializer %int.convert_checked.loc6_94.2 [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %.loc6_94.5: %i32 = converted %int.sdiv, %.loc6_94.4 [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %tuple.loc6_94: %tuple.type.d07 = tuple_value (%.loc6_94.3, %.loc6_94.5) [concrete = constants.%tuple]
+// CHECK:STDOUT:     %.loc6_95.2: %tuple.type.d07 = converted %.loc6_94.1, %tuple.loc6_94 [concrete = constants.%tuple]
+// CHECK:STDOUT:     %struct.loc6_95: %struct_type.a.b.fe2 = struct_value (%.loc6_65, %.loc6_95.2) [concrete = constants.%struct]
+// CHECK:STDOUT:     %.loc6_95.3: %struct_type.a.b.fe2 = converted %.loc6_95.1, %struct.loc6_95 [concrete = constants.%struct]
+// CHECK:STDOUT:     %.loc6_14: type = where_expr %.Self [concrete = constants.%I_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc6_20, %.loc6_48.3
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc6_54, %.loc6_95.3
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %I.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl.9be [concrete]
+// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness %I.impl_witness_table [concrete = constants.%I.impl_witness]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: %struct_type.a.b.fe2 = impl_witness_assoc_constant constants.%struct [concrete = constants.%struct]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @I {
+// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self.826]
+// CHECK:STDOUT:   %X: %struct_type.a.b.fe2 = assoc_const_decl @X [concrete] {
+// CHECK:STDOUT:     %assoc0: %I.assoc_type = assoc_entity element0, @I.%X [concrete = constants.%assoc0.e7f]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .X = @X.%assoc0
+// CHECK:STDOUT:   witness = (%X)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @X(@I.%Self: %I.type) {
+// CHECK:STDOUT:   assoc_const X:! %struct_type.a.b.fe2;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.9be: %.loc6_7.2 as %.loc6_14 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = file.%I.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @X(constants.%Self.826) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @X(constants.%I.facet) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_two_different_non_type.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %I.type: type = facet_type <@I> [concrete]
+// CHECK:STDOUT:   %Self.826: %I.type = bind_symbolic_name Self, 0 [symbolic]
+// CHECK:STDOUT:   %Bool.type: type = fn_type @Bool [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %Bool: %Bool.type = struct_value () [concrete]
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
+// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
+// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
+// CHECK:STDOUT:   %tuple.type.d07: type = tuple_type (%i32, %i32) [concrete]
+// CHECK:STDOUT:   %struct_type.a.b.fe2: type = struct_type {.a: bool, .b: %tuple.type.d07} [concrete]
+// CHECK:STDOUT:   %I.assoc_type: type = assoc_entity_type @I [concrete]
+// CHECK:STDOUT:   %assoc0.e7f: %I.assoc_type = assoc_entity element0, @I.%X [concrete]
+// CHECK:STDOUT:   %.Self: %I.type = bind_symbolic_name .Self [symbolic_self]
+// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
+// CHECK:STDOUT:   %I.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I [symbolic_self]
+// CHECK:STDOUT:   %I.facet: %I.type = facet_value %.Self.as_type, (%I.lookup_impl_witness) [symbolic_self]
+// CHECK:STDOUT:   %impl.elem0: %struct_type.a.b.fe2 = impl_witness_access %I.lookup_impl_witness, element0 [symbolic_self]
+// CHECK:STDOUT:   %true: bool = bool_literal true [concrete]
+// CHECK:STDOUT:   %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
+// CHECK:STDOUT:   %int_2.ecc: Core.IntLiteral = int_value 2 [concrete]
+// CHECK:STDOUT:   %tuple.type.f94: type = tuple_type (Core.IntLiteral, Core.IntLiteral) [concrete]
+// CHECK:STDOUT:   %struct_type.a.b.aa4: type = struct_type {.a: bool, .b: %tuple.type.f94} [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
+// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.205: type = facet_type <@ImplicitAs, @ImplicitAs(%i32)> [concrete]
+// CHECK:STDOUT:   %Convert.type.1b6: type = fn_type @Convert.1, @ImplicitAs(%i32) [concrete]
+// CHECK:STDOUT:   %To.c80: Core.IntLiteral = bind_symbolic_name To, 0 [symbolic]
+// CHECK:STDOUT:   %Convert.type.0f9: type = fn_type @Convert.2, @impl.4f9(%To.c80) [symbolic]
+// CHECK:STDOUT:   %Convert.f06: %Convert.type.0f9 = struct_value () [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.impl_witness.c75: <witness> = impl_witness imports.%ImplicitAs.impl_witness_table.a2f, @impl.4f9(%int_32) [concrete]
+// CHECK:STDOUT:   %Convert.type.035: type = fn_type @Convert.2, @impl.4f9(%int_32) [concrete]
+// CHECK:STDOUT:   %Convert.956: %Convert.type.035 = struct_value () [concrete]
+// CHECK:STDOUT:   %ImplicitAs.facet: %ImplicitAs.type.205 = facet_value Core.IntLiteral, (%ImplicitAs.impl_witness.c75) [concrete]
+// CHECK:STDOUT:   %.9c3: type = fn_type_with_self_type %Convert.type.1b6, %ImplicitAs.facet [concrete]
+// CHECK:STDOUT:   %Convert.bound.ab5: <bound method> = bound_method %int_1.5b8, %Convert.956 [concrete]
+// CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.956, @Convert.2(%int_32) [concrete]
+// CHECK:STDOUT:   %bound_method.9a1: <bound method> = bound_method %int_1.5b8, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_1.5d2: %i32 = int_value 1 [concrete]
+// CHECK:STDOUT:   %Convert.bound.ef9: <bound method> = bound_method %int_2.ecc, %Convert.956 [concrete]
+// CHECK:STDOUT:   %bound_method.b92: <bound method> = bound_method %int_2.ecc, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_2.ef8: %i32 = int_value 2 [concrete]
+// CHECK:STDOUT:   %tuple.21c: %tuple.type.d07 = tuple_value (%int_1.5d2, %int_2.ef8) [concrete]
+// CHECK:STDOUT:   %struct.682: %struct_type.a.b.fe2 = struct_value (%true, %tuple.21c) [concrete]
+// CHECK:STDOUT:   %false: bool = bool_literal false [concrete]
+// CHECK:STDOUT:   %int_3.1ba: Core.IntLiteral = int_value 3 [concrete]
+// CHECK:STDOUT:   %int_4.0c1: Core.IntLiteral = int_value 4 [concrete]
+// CHECK:STDOUT:   %Convert.bound.b30: <bound method> = bound_method %int_3.1ba, %Convert.956 [concrete]
+// CHECK:STDOUT:   %bound_method.047: <bound method> = bound_method %int_3.1ba, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_3.822: %i32 = int_value 3 [concrete]
+// CHECK:STDOUT:   %Convert.bound.ac3: <bound method> = bound_method %int_4.0c1, %Convert.956 [concrete]
+// CHECK:STDOUT:   %bound_method.1da: <bound method> = bound_method %int_4.0c1, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_4.940: %i32 = int_value 4 [concrete]
+// CHECK:STDOUT:   %tuple.ffd: %tuple.type.d07 = tuple_value (%int_3.822, %int_4.940) [concrete]
+// CHECK:STDOUT:   %struct.68c: %struct_type.a.b.fe2 = struct_value (%false, %tuple.ffd) [concrete]
+// CHECK:STDOUT:   %I_where.type: type = facet_type <@I where %impl.elem0 = %struct.682 and %impl.elem0 = %struct.68c> [concrete]
+// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness file.%I.impl_witness_table [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .Bool = %Core.Bool
+// CHECK:STDOUT:     .Int = %Core.Int
+// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.Bool: %Bool.type = import_ref Core//prelude/types/bool, Bool, loaded [concrete = constants.%Bool]
+// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/types/int, Int, loaded [concrete = constants.%Int.generic]
+// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/operators/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
+// CHECK:STDOUT:   %Core.import_ref.a5b: @impl.4f9.%Convert.type (%Convert.type.0f9) = import_ref Core//prelude/types/int, loc19_39, loaded [symbolic = @impl.4f9.%Convert (constants.%Convert.f06)]
+// CHECK:STDOUT:   %ImplicitAs.impl_witness_table.a2f = impl_witness_table (%Core.import_ref.a5b), @impl.4f9 [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .I = %I.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %I.decl: type = interface_decl @I [concrete = constants.%I.type] {} {}
+// CHECK:STDOUT:   impl_decl @impl.dd8 [concrete] {} {
+// CHECK:STDOUT:     %.loc10_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc10_7.2: type = converted %.loc10_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
+// CHECK:STDOUT:     %.Self: %I.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %.Self.ref.loc10_20: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %X.ref.loc10_20: %I.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0.e7f]
+// CHECK:STDOUT:     %.Self.as_type.loc10_20: type = facet_access_type %.Self.ref.loc10_20 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc10_20: type = converted %.Self.ref.loc10_20, %.Self.as_type.loc10_20 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc10_20: %struct_type.a.b.fe2 = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %true: bool = bool_literal true [concrete = constants.%true]
+// CHECK:STDOUT:     %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
+// CHECK:STDOUT:     %int_2: Core.IntLiteral = int_value 2 [concrete = constants.%int_2.ecc]
+// CHECK:STDOUT:     %.loc10_47.1: %tuple.type.f94 = tuple_literal (%int_1, %int_2)
+// CHECK:STDOUT:     %.loc10_48.1: %struct_type.a.b.aa4 = struct_literal (%true, %.loc10_47.1)
+// CHECK:STDOUT:     %impl.elem0.loc10_47.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:     %bound_method.loc10_47.1: <bound method> = bound_method %int_1, %impl.elem0.loc10_47.1 [concrete = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:     %specific_fn.loc10_47.1: <specific function> = specific_function %impl.elem0.loc10_47.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:     %bound_method.loc10_47.2: <bound method> = bound_method %int_1, %specific_fn.loc10_47.1 [concrete = constants.%bound_method.9a1]
+// CHECK:STDOUT:     %int.convert_checked.loc10_47.1: init %i32 = call %bound_method.loc10_47.2(%int_1) [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %.loc10_47.2: %i32 = value_of_initializer %int.convert_checked.loc10_47.1 [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %.loc10_47.3: %i32 = converted %int_1, %.loc10_47.2 [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:     %impl.elem0.loc10_47.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:     %bound_method.loc10_47.3: <bound method> = bound_method %int_2, %impl.elem0.loc10_47.2 [concrete = constants.%Convert.bound.ef9]
+// CHECK:STDOUT:     %specific_fn.loc10_47.2: <specific function> = specific_function %impl.elem0.loc10_47.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:     %bound_method.loc10_47.4: <bound method> = bound_method %int_2, %specific_fn.loc10_47.2 [concrete = constants.%bound_method.b92]
+// CHECK:STDOUT:     %int.convert_checked.loc10_47.2: init %i32 = call %bound_method.loc10_47.4(%int_2) [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %.loc10_47.4: %i32 = value_of_initializer %int.convert_checked.loc10_47.2 [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %.loc10_47.5: %i32 = converted %int_2, %.loc10_47.4 [concrete = constants.%int_2.ef8]
+// CHECK:STDOUT:     %tuple.loc10_47: %tuple.type.d07 = tuple_value (%.loc10_47.3, %.loc10_47.5) [concrete = constants.%tuple.21c]
+// CHECK:STDOUT:     %.loc10_48.2: %tuple.type.d07 = converted %.loc10_47.1, %tuple.loc10_47 [concrete = constants.%tuple.21c]
+// CHECK:STDOUT:     %struct.loc10_48: %struct_type.a.b.fe2 = struct_value (%true, %.loc10_48.2) [concrete = constants.%struct.682]
+// CHECK:STDOUT:     %.loc10_48.3: %struct_type.a.b.fe2 = converted %.loc10_48.1, %struct.loc10_48 [concrete = constants.%struct.682]
+// CHECK:STDOUT:     %.Self.ref.loc10_54: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
+// CHECK:STDOUT:     %X.ref.loc10_54: %I.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0.e7f]
+// CHECK:STDOUT:     %.Self.as_type.loc10_54: type = facet_access_type %.Self.ref.loc10_54 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %.loc10_54: type = converted %.Self.ref.loc10_54, %.Self.as_type.loc10_54 [symbolic_self = constants.%.Self.as_type]
+// CHECK:STDOUT:     %impl.elem0.loc10_54: %struct_type.a.b.fe2 = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
+// CHECK:STDOUT:     %false: bool = bool_literal false [concrete = constants.%false]
+// CHECK:STDOUT:     %int_3: Core.IntLiteral = int_value 3 [concrete = constants.%int_3.1ba]
+// CHECK:STDOUT:     %int_4: Core.IntLiteral = int_value 4 [concrete = constants.%int_4.0c1]
+// CHECK:STDOUT:     %.loc10_82.1: %tuple.type.f94 = tuple_literal (%int_3, %int_4)
+// CHECK:STDOUT:     %.loc10_83.1: %struct_type.a.b.aa4 = struct_literal (%false, %.loc10_82.1)
+// CHECK:STDOUT:     %impl.elem0.loc10_82.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:     %bound_method.loc10_82.1: <bound method> = bound_method %int_3, %impl.elem0.loc10_82.1 [concrete = constants.%Convert.bound.b30]
+// CHECK:STDOUT:     %specific_fn.loc10_82.1: <specific function> = specific_function %impl.elem0.loc10_82.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:     %bound_method.loc10_82.2: <bound method> = bound_method %int_3, %specific_fn.loc10_82.1 [concrete = constants.%bound_method.047]
+// CHECK:STDOUT:     %int.convert_checked.loc10_82.1: init %i32 = call %bound_method.loc10_82.2(%int_3) [concrete = constants.%int_3.822]
+// CHECK:STDOUT:     %.loc10_82.2: %i32 = value_of_initializer %int.convert_checked.loc10_82.1 [concrete = constants.%int_3.822]
+// CHECK:STDOUT:     %.loc10_82.3: %i32 = converted %int_3, %.loc10_82.2 [concrete = constants.%int_3.822]
+// CHECK:STDOUT:     %impl.elem0.loc10_82.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:     %bound_method.loc10_82.3: <bound method> = bound_method %int_4, %impl.elem0.loc10_82.2 [concrete = constants.%Convert.bound.ac3]
+// CHECK:STDOUT:     %specific_fn.loc10_82.2: <specific function> = specific_function %impl.elem0.loc10_82.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:     %bound_method.loc10_82.4: <bound method> = bound_method %int_4, %specific_fn.loc10_82.2 [concrete = constants.%bound_method.1da]
+// CHECK:STDOUT:     %int.convert_checked.loc10_82.2: init %i32 = call %bound_method.loc10_82.4(%int_4) [concrete = constants.%int_4.940]
+// CHECK:STDOUT:     %.loc10_82.4: %i32 = value_of_initializer %int.convert_checked.loc10_82.2 [concrete = constants.%int_4.940]
+// CHECK:STDOUT:     %.loc10_82.5: %i32 = converted %int_4, %.loc10_82.4 [concrete = constants.%int_4.940]
+// CHECK:STDOUT:     %tuple.loc10_82: %tuple.type.d07 = tuple_value (%.loc10_82.3, %.loc10_82.5) [concrete = constants.%tuple.ffd]
+// CHECK:STDOUT:     %.loc10_83.2: %tuple.type.d07 = converted %.loc10_82.1, %tuple.loc10_82 [concrete = constants.%tuple.ffd]
+// CHECK:STDOUT:     %struct.loc10_83: %struct_type.a.b.fe2 = struct_value (%false, %.loc10_83.2) [concrete = constants.%struct.68c]
+// CHECK:STDOUT:     %.loc10_83.3: %struct_type.a.b.fe2 = converted %.loc10_83.1, %struct.loc10_83 [concrete = constants.%struct.68c]
+// CHECK:STDOUT:     %.loc10_14: type = where_expr %.Self [concrete = constants.%I_where.type] {
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc10_20, %.loc10_48.3
+// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc10_54, %.loc10_83.3
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %I.impl_witness_table = impl_witness_table (<error>), @impl.dd8 [concrete]
+// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness %I.impl_witness_table [concrete = constants.%I.impl_witness]
+// CHECK:STDOUT:   %impl_witness_assoc_constant: %struct_type.a.b.fe2 = impl_witness_assoc_constant constants.%struct.682 [concrete = constants.%struct.682]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: interface @I {
+// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self.826]
+// CHECK:STDOUT:   %X: %struct_type.a.b.fe2 = assoc_const_decl @X [concrete] {
+// CHECK:STDOUT:     %assoc0: %I.assoc_type = assoc_entity element0, @I.%X [concrete = constants.%assoc0.e7f]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = %Self
+// CHECK:STDOUT:   .X = @X.%assoc0
+// CHECK:STDOUT:   witness = (%X)
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic assoc_const @X(@I.%Self: %I.type) {
+// CHECK:STDOUT:   assoc_const X:! %struct_type.a.b.fe2;
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.dd8: %.loc10_7.2 as %.loc10_14 {
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   witness = file.%I.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @X(constants.%Self.826) {}
+// CHECK:STDOUT:
+// CHECK:STDOUT: specific @X(constants.%I.facet) {}
+// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon b/toolchain/check/testdata/impl/impl_self_as.carbon
similarity index 97%
rename from toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon
rename to toolchain/check/testdata/impl/impl_self_as.carbon
index 1ee890073628..5d8e1fc6747f 100644
--- a/toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon
+++ b/toolchain/check/testdata/impl/impl_self_as.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/impl_self_as.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/impl_self_as.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/impl_self_as.carbon
 
 // --- match.carbon
 library "[[@TEST_NAME]]";
diff --git a/toolchain/check/testdata/impl/no_prelude/impl_thunk.carbon b/toolchain/check/testdata/impl/impl_thunk.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/impl_thunk.carbon
rename to toolchain/check/testdata/impl/impl_thunk.carbon
index 7d8677f9a9a4..c55d172252c4 100644
--- a/toolchain/check/testdata/impl/no_prelude/impl_thunk.carbon
+++ b/toolchain/check/testdata/impl/impl_thunk.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/impl_thunk.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/impl_thunk.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/impl_thunk.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/impl_thunk.carbon
 
 // --- no_thunk_param_name_differs.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon b/toolchain/check/testdata/impl/impl_where_redecl.carbon
similarity index 95%
rename from toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon
rename to toolchain/check/testdata/impl/impl_where_redecl.carbon
index b61e06527c99..20aaf4ce4879 100644
--- a/toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon
+++ b/toolchain/check/testdata/impl/impl_where_redecl.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/impl_where_redecl.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/impl_where_redecl.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/impl_where_redecl.carbon
 
 // `impl` declarations only match when they are the same syntactically.
 
diff --git a/toolchain/check/testdata/impl/no_prelude/import_builtin_call.carbon b/toolchain/check/testdata/impl/import_builtin_call.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/import_builtin_call.carbon
rename to toolchain/check/testdata/impl/import_builtin_call.carbon
index bac3e7b4fae6..dbec8982af65 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_builtin_call.carbon
+++ b/toolchain/check/testdata/impl/import_builtin_call.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/import_builtin_call.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/import_builtin_call.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/import_builtin_call.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/import_builtin_call.carbon
 
 // --- generic_impl.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/import_compound.carbon b/toolchain/check/testdata/impl/import_compound.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/import_compound.carbon
rename to toolchain/check/testdata/impl/import_compound.carbon
index 08a81c02f921..e8405b97f497 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_compound.carbon
+++ b/toolchain/check/testdata/impl/import_compound.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/import_compound.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/import_compound.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/import_compound.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/import_compound.carbon
 
 // --- core.carbon
 package Core;
diff --git a/toolchain/check/testdata/impl/no_prelude/import_extend_impl.carbon b/toolchain/check/testdata/impl/import_extend_impl.carbon
similarity index 98%
rename from toolchain/check/testdata/impl/no_prelude/import_extend_impl.carbon
rename to toolchain/check/testdata/impl/import_extend_impl.carbon
index 2b13ac1e393b..b4561b17ebc9 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_extend_impl.carbon
+++ b/toolchain/check/testdata/impl/import_extend_impl.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/import_extend_impl.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/import_extend_impl.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/import_extend_impl.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/import_extend_impl.carbon
 
 // --- extend_impl_library.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/import_generic.carbon b/toolchain/check/testdata/impl/import_generic.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/import_generic.carbon
rename to toolchain/check/testdata/impl/import_generic.carbon
index 06d765b44f13..ba992c477d35 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_generic.carbon
+++ b/toolchain/check/testdata/impl/import_generic.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/import_generic.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/import_generic.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/import_generic.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/import_generic.carbon
 
 // --- import_generic.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/import_impl_with_no_interface.carbon b/toolchain/check/testdata/impl/import_impl_with_no_interface.carbon
similarity index 82%
rename from toolchain/check/testdata/impl/no_prelude/import_impl_with_no_interface.carbon
rename to toolchain/check/testdata/impl/import_impl_with_no_interface.carbon
index 9f468385a7b0..57294b19ca53 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_impl_with_no_interface.carbon
+++ b/toolchain/check/testdata/impl/import_impl_with_no_interface.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/import_impl_with_no_interface.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/import_impl_with_no_interface.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/import_impl_with_no_interface.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/import_impl_with_no_interface.carbon
 
 // --- fail_lib.carbon
 library "[[@TEST_NAME]]";
diff --git a/toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon b/toolchain/check/testdata/impl/import_interface_assoc_const.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon
rename to toolchain/check/testdata/impl/import_interface_assoc_const.carbon
index a59c6afd670b..898fea021f47 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon
+++ b/toolchain/check/testdata/impl/import_interface_assoc_const.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/import_interface_assoc_const.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/import_interface_assoc_const.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/import_interface_assoc_const.carbon
 
 // --- interface.carbon
 library "[[@TEST_NAME]]";
diff --git a/toolchain/check/testdata/impl/no_prelude/import_thunk.carbon b/toolchain/check/testdata/impl/import_thunk.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/import_thunk.carbon
rename to toolchain/check/testdata/impl/import_thunk.carbon
index 7b7377684ce6..57253aaafc03 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_thunk.carbon
+++ b/toolchain/check/testdata/impl/import_thunk.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/import_thunk.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/import_thunk.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/import_thunk.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/import_thunk.carbon
 
 // --- a.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon b/toolchain/check/testdata/impl/import_use_generic.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon
rename to toolchain/check/testdata/impl/import_use_generic.carbon
index 80a06a56d5f6..8307ade0e972 100644
--- a/toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon
+++ b/toolchain/check/testdata/impl/import_use_generic.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/import_use_generic.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/import_use_generic.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/import_use_generic.carbon
 
 // --- import_generic.carbon
 
diff --git a/toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon b/toolchain/check/testdata/impl/lookup/specific_args.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon
rename to toolchain/check/testdata/impl/lookup/specific_args.carbon
index a4fa155e68f5..b1afddf9fc35 100644
--- a/toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon
+++ b/toolchain/check/testdata/impl/lookup/specific_args.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/lookup/specific_args.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/lookup/no_prelude/specific_args.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/lookup/specific_args.carbon
 
 // --- types.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/name_poisoning.carbon b/toolchain/check/testdata/impl/name_poisoning.carbon
similarity index 91%
rename from toolchain/check/testdata/impl/no_prelude/name_poisoning.carbon
rename to toolchain/check/testdata/impl/name_poisoning.carbon
index ee913df58ffb..cd9c7ef0f317 100644
--- a/toolchain/check/testdata/impl/no_prelude/name_poisoning.carbon
+++ b/toolchain/check/testdata/impl/name_poisoning.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/name_poisoning.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/name_poisoning.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/name_poisoning.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/name_poisoning.carbon
 
 // --- using_poisoned_name_in_impl.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon b/toolchain/check/testdata/impl/no_definition_in_impl_file.carbon
similarity index 98%
rename from toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon
rename to toolchain/check/testdata/impl/no_definition_in_impl_file.carbon
index 907b488a09b1..df17fe1282c4 100644
--- a/toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon
+++ b/toolchain/check/testdata/impl/no_definition_in_impl_file.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_definition_in_impl_file.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/no_definition_in_impl_file.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_definition_in_impl_file.carbon
 
 // --- fail_decl_in_api_definition_in_impl.carbon
 
diff --git a/toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon b/toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon
deleted file mode 100644
index 37414a323622..000000000000
--- a/toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon
+++ /dev/null
@@ -1,1265 +0,0 @@
-// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
-// Exceptions. See /LICENSE for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-// TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
-//
-// AUTOUPDATE
-// TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon
-// TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/impl_assoc_const.carbon
-
-// --- success.carbon
-library "[[@TEST_NAME]]";
-
-interface I { let T:! type; }
-
-impl () as I where .T = {} {}
-
-// --- redecl.carbon
-library "[[@TEST_NAME]]";
-
-interface I2 { let T2:! type; }
-
-impl () as I2 where .T2 = {};
-impl () as I2 where .T2 = {} {}
-
-// --- fail_redecl_adds_rewrites.carbon
-library "[[@TEST_NAME]]";
-
-interface I3 { let T3:! type; }
-
-// CHECK:STDERR: fail_redecl_adds_rewrites.carbon:[[@LINE+4]]:1: error: impl declared but not defined [ImplMissingDefinition]
-// CHECK:STDERR: impl () as I3;
-// CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR:
-impl () as I3;
-impl () as I3 where .T3 = {} {}
-
-// --- fail_mismatch.carbon
-library "[[@TEST_NAME]]";
-
-interface J { let U:! type; }
-
-// CHECK:STDERR: fail_mismatch.carbon:[[@LINE+4]]:1: error: impl declared but not defined [ImplMissingDefinition]
-// CHECK:STDERR: impl () as J where .U = {};
-// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR:
-impl () as J where .U = {};
-impl () as J where .U = () {}
-
-// --- fail_mismatch_bad_value.carbon
-library "[[@TEST_NAME]]";
-
-interface I4 {
-  let T4:! type;
-  let T5:! type;
-  let T6:! type;
-}
-
-// CHECK:STDERR: fail_mismatch_bad_value.carbon:[[@LINE+8]]:27: error: name `BAD1` not found [NameNotFound]
-// CHECK:STDERR: impl () as I4 where .T4 = BAD1 and .T5 = {.a: {}} and .T6 = BAD2;
-// CHECK:STDERR:                           ^~~~
-// CHECK:STDERR:
-// CHECK:STDERR: fail_mismatch_bad_value.carbon:[[@LINE+4]]:61: error: name `BAD2` not found [NameNotFound]
-// CHECK:STDERR: impl () as I4 where .T4 = BAD1 and .T5 = {.a: {}} and .T6 = BAD2;
-// CHECK:STDERR:                                                             ^~~~
-// CHECK:STDERR:
-impl () as I4 where .T4 = BAD1 and .T5 = {.a: {}} and .T6 = BAD2;
-
-// CHECK:STDERR: fail_mismatch_bad_value.carbon:[[@LINE+8]]:46: error: name `BAD3` not found [NameNotFound]
-// CHECK:STDERR: impl () as I4 where .T4 = {.b: {}} and .T5 = BAD3 and .T6 = BAD4 {}
-// CHECK:STDERR:                                              ^~~~
-// CHECK:STDERR:
-// CHECK:STDERR: fail_mismatch_bad_value.carbon:[[@LINE+4]]:61: error: name `BAD4` not found [NameNotFound]
-// CHECK:STDERR: impl () as I4 where .T4 = {.b: {}} and .T5 = BAD3 and .T6 = BAD4 {}
-// CHECK:STDERR:                                                             ^~~~
-// CHECK:STDERR:
-impl () as I4 where .T4 = {.b: {}} and .T5 = BAD3 and .T6 = BAD4 {}
-
-// --- fail_missing_on_definition.carbon
-library "[[@TEST_NAME]]";
-
-interface K { let V:! type; }
-
-impl () as K where .V = {};
-// CHECK:STDERR: fail_missing_on_definition.carbon:[[@LINE+11]]:1: error: associated constant V not given a value in impl of interface K [ImplAssociatedConstantNeedsValue]
-// CHECK:STDERR: impl () as K {}
-// CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_missing_on_definition.carbon:[[@LINE-6]]:19: note: associated constant declared here [AssociatedConstantHere]
-// CHECK:STDERR: interface K { let V:! type; }
-// CHECK:STDERR:                   ^~~~~~~~
-// CHECK:STDERR:
-// CHECK:STDERR: fail_missing_on_definition.carbon:[[@LINE-8]]:1: error: impl declared but not defined [ImplMissingDefinition]
-// CHECK:STDERR: impl () as K where .V = {};
-// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR:
-impl () as K {}
-
-// --- fail_two_different.carbon
-library "[[@TEST_NAME]]";
-
-interface L { let W:! type; }
-
-// CHECK:STDERR: fail_two_different.carbon:[[@LINE+4]]:12: error: associated constant W given two different values `()` and `{}` [AssociatedConstantWithDifferentValues]
-// CHECK:STDERR: impl () as L where .W = {} and .W = () {}
-// CHECK:STDERR:            ^~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR:
-impl () as L where .W = {} and .W = () {}
-
-// --- fail_two_different_first_bad.carbon
-library "[[@TEST_NAME]]";
-
-interface L2 { let W2:! type; }
-
-// CHECK:STDERR: fail_two_different_first_bad.carbon:[[@LINE+4]]:27: error: name `BAD5` not found [NameNotFound]
-// CHECK:STDERR: impl () as L2 where .W2 = BAD5 and .W2 = () {}
-// CHECK:STDERR:                           ^~~~
-// CHECK:STDERR:
-impl () as L2 where .W2 = BAD5 and .W2 = () {}
-
-// --- fail_two_different_second_bad.carbon
-library "[[@TEST_NAME]]";
-
-interface L3 { let W3:! type; }
-
-// CHECK:STDERR: fail_two_different_second_bad.carbon:[[@LINE+4]]:40: error: name `BAD6` not found [NameNotFound]
-// CHECK:STDERR: impl () as L3 where .W3 = {} and .W3 = BAD6 {}
-// CHECK:STDERR:                                        ^~~~
-// CHECK:STDERR:
-impl () as L3 where .W3 = {} and .W3 = BAD6 {}
-
-// --- fail_two_different_both_bad.carbon
-library "[[@TEST_NAME]]";
-
-interface L4 { let W4:! type; }
-
-// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+8]]:27: error: name `BAD7` not found [NameNotFound]
-// CHECK:STDERR: impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
-// CHECK:STDERR:                           ^~~~
-// CHECK:STDERR:
-// CHECK:STDERR: fail_two_different_both_bad.carbon:[[@LINE+4]]:42: error: name `BAD8` not found [NameNotFound]
-// CHECK:STDERR: impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
-// CHECK:STDERR:                                          ^~~~
-// CHECK:STDERR:
-impl () as L4 where .W4 = BAD7 and .W4 = BAD8 {}
-
-// --- repeated.carbon
-library "[[@TEST_NAME]]";
-
-interface M { let X:! type; }
-
-impl () as M where .X = {} and .X = {} {}
-
-// --- non-type.carbon
-library "[[@TEST_NAME]]";
-
-interface N {
-  let Y:! {.a: {}};
-}
-
-impl () as N where .Y = {.a = {}} { }
-
-// --- fail_where_rewrite_function.carbon
-library "[[@TEST_NAME]]";
-
-interface IF { fn F(); }
-
-class CD { }
-
-// CHECK:STDERR: fail_where_rewrite_function.carbon:[[@LINE+4]]:12: error: rewrite specified for associated function F [RewriteForAssociatedFunction]
-// CHECK:STDERR: impl CD as IF where .F = 0 {
-// CHECK:STDERR:            ^~~~~~~~~~~~~~~
-// CHECK:STDERR:
-impl CD as IF where .F = 0 {
-  fn F() {}
-}
-
-// CHECK:STDOUT: --- success.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %I.type: type = facet_type <@I> [concrete]
-// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %I.assoc_type: type = assoc_entity_type @I [concrete]
-// CHECK:STDOUT:   %assoc0: %I.assoc_type = assoc_entity element0, @I.%T [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %I.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %I.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I [symbolic_self]
-// CHECK:STDOUT:   %I.facet: %I.type = facet_value %.Self.as_type, (%I.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %I.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %I_where.type: type = facet_type <@I where %impl.elem0 = %empty_struct_type> [concrete]
-// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness file.%I.impl_witness_table [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .I = %I.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I.decl: type = interface_decl @I [concrete = constants.%I.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc5_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc5_7.2: type = converted %.loc5_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I.ref: type = name_ref I, file.%I.decl [concrete = constants.%I.type]
-// CHECK:STDOUT:     %.Self: %I.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref: %I.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T.ref: %I.assoc_type = name_ref T, @T.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc5_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%I.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc5_26.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc5_26.2: type = converted %.loc5_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.loc5_14: type = where_expr %.Self [concrete = constants.%I_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc5_26.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl [concrete]
-// CHECK:STDOUT:   %I.impl_witness: <witness> = impl_witness %I.impl_witness_table [concrete = constants.%I.impl_witness]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @I {
-// CHECK:STDOUT:   %Self: %I.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %T: type = assoc_const_decl @T [concrete] {
-// CHECK:STDOUT:     %assoc0: %I.assoc_type = assoc_entity element0, @I.%T [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .T = @T.%assoc0
-// CHECK:STDOUT:   witness = (%T)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @T(@I.%Self: %I.type) {
-// CHECK:STDOUT:   assoc_const T:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc5_7.2 as %.loc5_14 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%I.impl_witness
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T(constants.%I.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- redecl.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %I2.type: type = facet_type <@I2> [concrete]
-// CHECK:STDOUT:   %Self: %I2.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %I2.assoc_type: type = assoc_entity_type @I2 [concrete]
-// CHECK:STDOUT:   %assoc0: %I2.assoc_type = assoc_entity element0, @I2.%T2 [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %I2.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %I2.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I2 [symbolic_self]
-// CHECK:STDOUT:   %I2.facet: %I2.type = facet_value %.Self.as_type, (%I2.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %I2.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %I2_where.type: type = facet_type <@I2 where %impl.elem0 = %empty_struct_type> [concrete]
-// CHECK:STDOUT:   %I2.impl_witness: <witness> = impl_witness file.%I2.impl_witness_table [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .I2 = %I2.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I2.decl: type = interface_decl @I2 [concrete = constants.%I2.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc5_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc5_7.2: type = converted %.loc5_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I2.ref.loc5: type = name_ref I2, file.%I2.decl [concrete = constants.%I2.type]
-// CHECK:STDOUT:     %.Self.1: %I2.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc5: %I2.type = name_ref .Self, %.Self.1 [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T2.ref.loc5: %I2.assoc_type = name_ref T2, @T2.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc5: type = facet_access_type %.Self.ref.loc5 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc5_21: type = converted %.Self.ref.loc5, %.Self.as_type.loc5 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc5: type = impl_witness_access constants.%I2.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc5_28.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc5_28.2: type = converted %.loc5_28.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.loc5_15: type = where_expr %.Self.1 [concrete = constants.%I2_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc5, %.loc5_28.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I2.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl [concrete]
-// CHECK:STDOUT:   %I2.impl_witness: <witness> = impl_witness %I2.impl_witness_table [concrete = constants.%I2.impl_witness]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc6_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc6_7.2: type = converted %.loc6_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I2.ref.loc6: type = name_ref I2, file.%I2.decl [concrete = constants.%I2.type]
-// CHECK:STDOUT:     %.Self.2: %I2.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc6: %I2.type = name_ref .Self, %.Self.2 [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T2.ref.loc6: %I2.assoc_type = name_ref T2, @T2.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc6: type = facet_access_type %.Self.ref.loc6 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc6_21: type = converted %.Self.ref.loc6, %.Self.as_type.loc6 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc6: type = impl_witness_access constants.%I2.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc6_28.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc6_28.2: type = converted %.loc6_28.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.loc6_15: type = where_expr %.Self.2 [concrete = constants.%I2_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc6, %.loc6_28.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @I2 {
-// CHECK:STDOUT:   %Self: %I2.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %T2: type = assoc_const_decl @T2 [concrete] {
-// CHECK:STDOUT:     %assoc0: %I2.assoc_type = assoc_entity element0, @I2.%T2 [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .T2 = @T2.%assoc0
-// CHECK:STDOUT:   witness = (%T2)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @T2(@I2.%Self: %I2.type) {
-// CHECK:STDOUT:   assoc_const T2:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc5_7.2 as %.loc5_15 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%I2.impl_witness
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T2(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T2(constants.%I2.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_redecl_adds_rewrites.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %I3.type: type = facet_type <@I3> [concrete]
-// CHECK:STDOUT:   %Self: %I3.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %I3.assoc_type: type = assoc_entity_type @I3 [concrete]
-// CHECK:STDOUT:   %assoc0: %I3.assoc_type = assoc_entity element0, @I3.%T3 [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %I3.impl_witness.c9d: <witness> = impl_witness file.%I3.impl_witness_table.loc9 [concrete]
-// CHECK:STDOUT:   %.Self: %I3.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %I3.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I3 [symbolic_self]
-// CHECK:STDOUT:   %I3.facet: %I3.type = facet_value %.Self.as_type, (%I3.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %I3.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %I3_where.type: type = facet_type <@I3 where %impl.elem0 = %empty_struct_type> [concrete]
-// CHECK:STDOUT:   %I3.impl_witness.ea7: <witness> = impl_witness file.%I3.impl_witness_table.loc10 [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .I3 = %I3.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I3.decl: type = interface_decl @I3 [concrete = constants.%I3.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl.b46 [concrete] {} {
-// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I3.ref: type = name_ref I3, file.%I3.decl [concrete = constants.%I3.type]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I3.impl_witness_table.loc9 = impl_witness_table (), @impl.b46 [concrete]
-// CHECK:STDOUT:   %I3.impl_witness.loc9: <witness> = impl_witness %I3.impl_witness_table.loc9 [concrete = constants.%I3.impl_witness.c9d]
-// CHECK:STDOUT:   impl_decl @impl.4b6 [concrete] {} {
-// CHECK:STDOUT:     %.loc10_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc10_7.2: type = converted %.loc10_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I3.ref: type = name_ref I3, file.%I3.decl [concrete = constants.%I3.type]
-// CHECK:STDOUT:     %.Self: %I3.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref: %I3.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T3.ref: %I3.assoc_type = name_ref T3, @T3.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc10_21: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%I3.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc10_28.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc10_28.2: type = converted %.loc10_28.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.loc10_15: type = where_expr %.Self [concrete = constants.%I3_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc10_28.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I3.impl_witness_table.loc10 = impl_witness_table (%impl_witness_assoc_constant), @impl.4b6 [concrete]
-// CHECK:STDOUT:   %I3.impl_witness.loc10: <witness> = impl_witness %I3.impl_witness_table.loc10 [concrete = constants.%I3.impl_witness.ea7]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @I3 {
-// CHECK:STDOUT:   %Self: %I3.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %T3: type = assoc_const_decl @T3 [concrete] {
-// CHECK:STDOUT:     %assoc0: %I3.assoc_type = assoc_entity element0, @I3.%T3 [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .T3 = @T3.%assoc0
-// CHECK:STDOUT:   witness = (%T3)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @T3(@I3.%Self: %I3.type) {
-// CHECK:STDOUT:   assoc_const T3:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.b46: %.loc9_7.2 as %I3.ref;
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.4b6: %.loc10_7.2 as %.loc10_15 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%I3.impl_witness.loc10
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T3(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T3(constants.%I3.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_mismatch.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %J.type: type = facet_type <@J> [concrete]
-// CHECK:STDOUT:   %Self: %J.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %J.assoc_type: type = assoc_entity_type @J [concrete]
-// CHECK:STDOUT:   %assoc0: %J.assoc_type = assoc_entity element0, @J.%U [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %J.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %J.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @J [symbolic_self]
-// CHECK:STDOUT:   %J.facet: %J.type = facet_value %.Self.as_type, (%J.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %J.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %J_where.type.49a: type = facet_type <@J where %impl.elem0 = %empty_struct_type> [concrete]
-// CHECK:STDOUT:   %J.impl_witness.2a1: <witness> = impl_witness file.%J.impl_witness_table.loc9 [concrete]
-// CHECK:STDOUT:   %J_where.type.344: type = facet_type <@J where %impl.elem0 = %empty_tuple.type> [concrete]
-// CHECK:STDOUT:   %J.impl_witness.006: <witness> = impl_witness file.%J.impl_witness_table.loc10 [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .J = %J.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %J.decl: type = interface_decl @J [concrete = constants.%J.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl.3df [concrete] {} {
-// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %J.ref: type = name_ref J, file.%J.decl [concrete = constants.%J.type]
-// CHECK:STDOUT:     %.Self: %J.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref: %J.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %U.ref: %J.assoc_type = name_ref U, @U.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc9_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%J.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc9_26.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc9_26.2: type = converted %.loc9_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.loc9_14: type = where_expr %.Self [concrete = constants.%J_where.type.49a] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc9_26.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %J.impl_witness_table.loc9 = impl_witness_table (%impl_witness_assoc_constant.loc9), @impl.3df [concrete]
-// CHECK:STDOUT:   %J.impl_witness.loc9: <witness> = impl_witness %J.impl_witness_table.loc9 [concrete = constants.%J.impl_witness.2a1]
-// CHECK:STDOUT:   %impl_witness_assoc_constant.loc9: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   impl_decl @impl.153 [concrete] {} {
-// CHECK:STDOUT:     %.loc10_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc10_7.2: type = converted %.loc10_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %J.ref: type = name_ref J, file.%J.decl [concrete = constants.%J.type]
-// CHECK:STDOUT:     %.Self: %J.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref: %J.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %U.ref: %J.assoc_type = name_ref U, @U.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc10_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%J.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc10_26.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc10_26.2: type = converted %.loc10_26.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %.loc10_14: type = where_expr %.Self [concrete = constants.%J_where.type.344] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc10_26.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %J.impl_witness_table.loc10 = impl_witness_table (%impl_witness_assoc_constant.loc10), @impl.153 [concrete]
-// CHECK:STDOUT:   %J.impl_witness.loc10: <witness> = impl_witness %J.impl_witness_table.loc10 [concrete = constants.%J.impl_witness.006]
-// CHECK:STDOUT:   %impl_witness_assoc_constant.loc10: type = impl_witness_assoc_constant constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @J {
-// CHECK:STDOUT:   %Self: %J.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %U: type = assoc_const_decl @U [concrete] {
-// CHECK:STDOUT:     %assoc0: %J.assoc_type = assoc_entity element0, @J.%U [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .U = @U.%assoc0
-// CHECK:STDOUT:   witness = (%U)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @U(@J.%Self: %J.type) {
-// CHECK:STDOUT:   assoc_const U:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.3df: %.loc9_7.2 as %.loc9_14;
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.153: %.loc10_7.2 as %.loc10_14 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%J.impl_witness.loc10
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @U(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @U(constants.%J.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_mismatch_bad_value.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %I4.type: type = facet_type <@I4> [concrete]
-// CHECK:STDOUT:   %Self: %I4.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %I4.assoc_type: type = assoc_entity_type @I4 [concrete]
-// CHECK:STDOUT:   %assoc0: %I4.assoc_type = assoc_entity element0, @I4.%T4 [concrete]
-// CHECK:STDOUT:   %assoc1: %I4.assoc_type = assoc_entity element1, @I4.%T5 [concrete]
-// CHECK:STDOUT:   %assoc2: %I4.assoc_type = assoc_entity element2, @I4.%T6 [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %I4.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %I4.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @I4 [symbolic_self]
-// CHECK:STDOUT:   %I4.facet: %I4.type = facet_value %.Self.as_type, (%I4.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %I4.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %impl.elem1: type = impl_witness_access %I4.lookup_impl_witness, element1 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %struct_type.a: type = struct_type {.a: %empty_struct_type} [concrete]
-// CHECK:STDOUT:   %impl.elem2: type = impl_witness_access %I4.lookup_impl_witness, element2 [symbolic_self]
-// CHECK:STDOUT:   %struct_type.b: type = struct_type {.b: %empty_struct_type} [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .I4 = %I4.decl
-// CHECK:STDOUT:     .BAD1 = <poisoned>
-// CHECK:STDOUT:     .BAD2 = <poisoned>
-// CHECK:STDOUT:     .BAD3 = <poisoned>
-// CHECK:STDOUT:     .BAD4 = <poisoned>
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %I4.decl: type = interface_decl @I4 [concrete = constants.%I4.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl.de506c.1 [concrete] {} {
-// CHECK:STDOUT:     %.loc17_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc17_7.2: type = converted %.loc17_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I4.ref: type = name_ref I4, file.%I4.decl [concrete = constants.%I4.type]
-// CHECK:STDOUT:     %.Self: %I4.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc17_21: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T4.ref: %I4.assoc_type = name_ref T4, @T4.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc17_21: type = facet_access_type %.Self.ref.loc17_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc17_21: type = converted %.Self.ref.loc17_21, %.Self.as_type.loc17_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%I4.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %BAD1.ref: <error> = name_ref BAD1, <error> [concrete = <error>]
-// CHECK:STDOUT:     %.Self.ref.loc17_36: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T5.ref: %I4.assoc_type = name_ref T5, @T5.%assoc1 [concrete = constants.%assoc1]
-// CHECK:STDOUT:     %.Self.as_type.loc17_36: type = facet_access_type %.Self.ref.loc17_36 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc17_36: type = converted %.Self.ref.loc17_36, %.Self.as_type.loc17_36 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem1: type = impl_witness_access constants.%I4.lookup_impl_witness, element1 [symbolic_self = constants.%impl.elem1]
-// CHECK:STDOUT:     %.loc17_48.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc17_48.2: type = converted %.loc17_48.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %struct_type.a: type = struct_type {.a: %empty_struct_type} [concrete = constants.%struct_type.a]
-// CHECK:STDOUT:     %.Self.ref.loc17_55: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T6.ref: %I4.assoc_type = name_ref T6, @T6.%assoc2 [concrete = constants.%assoc2]
-// CHECK:STDOUT:     %.Self.as_type.loc17_55: type = facet_access_type %.Self.ref.loc17_55 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc17_55: type = converted %.Self.ref.loc17_55, %.Self.as_type.loc17_55 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem2: type = impl_witness_access constants.%I4.lookup_impl_witness, element2 [symbolic_self = constants.%impl.elem2]
-// CHECK:STDOUT:     %BAD2.ref: <error> = name_ref BAD2, <error> [concrete = <error>]
-// CHECK:STDOUT:     %.loc17_15: type = where_expr %.Self [concrete = <error>] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, <error>
-// CHECK:STDOUT:       requirement_rewrite %impl.elem1, %struct_type.a
-// CHECK:STDOUT:       requirement_rewrite %impl.elem2, <error>
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   impl_decl @impl.de506c.2 [concrete] {} {
-// CHECK:STDOUT:     %.loc27_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc27_7.2: type = converted %.loc27_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %I4.ref: type = name_ref I4, file.%I4.decl [concrete = constants.%I4.type]
-// CHECK:STDOUT:     %.Self: %I4.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc27_21: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T4.ref: %I4.assoc_type = name_ref T4, @T4.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc27_21: type = facet_access_type %.Self.ref.loc27_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc27_21: type = converted %.Self.ref.loc27_21, %.Self.as_type.loc27_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%I4.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc27_33.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc27_33.2: type = converted %.loc27_33.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %struct_type.b: type = struct_type {.b: %empty_struct_type} [concrete = constants.%struct_type.b]
-// CHECK:STDOUT:     %.Self.ref.loc27_40: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T5.ref: %I4.assoc_type = name_ref T5, @T5.%assoc1 [concrete = constants.%assoc1]
-// CHECK:STDOUT:     %.Self.as_type.loc27_40: type = facet_access_type %.Self.ref.loc27_40 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc27_40: type = converted %.Self.ref.loc27_40, %.Self.as_type.loc27_40 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem1: type = impl_witness_access constants.%I4.lookup_impl_witness, element1 [symbolic_self = constants.%impl.elem1]
-// CHECK:STDOUT:     %BAD3.ref: <error> = name_ref BAD3, <error> [concrete = <error>]
-// CHECK:STDOUT:     %.Self.ref.loc27_55: %I4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %T6.ref: %I4.assoc_type = name_ref T6, @T6.%assoc2 [concrete = constants.%assoc2]
-// CHECK:STDOUT:     %.Self.as_type.loc27_55: type = facet_access_type %.Self.ref.loc27_55 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc27_55: type = converted %.Self.ref.loc27_55, %.Self.as_type.loc27_55 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem2: type = impl_witness_access constants.%I4.lookup_impl_witness, element2 [symbolic_self = constants.%impl.elem2]
-// CHECK:STDOUT:     %BAD4.ref: <error> = name_ref BAD4, <error> [concrete = <error>]
-// CHECK:STDOUT:     %.loc27_15: type = where_expr %.Self [concrete = <error>] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %struct_type.b
-// CHECK:STDOUT:       requirement_rewrite %impl.elem1, <error>
-// CHECK:STDOUT:       requirement_rewrite %impl.elem2, <error>
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @I4 {
-// CHECK:STDOUT:   %Self: %I4.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %T4: type = assoc_const_decl @T4 [concrete] {
-// CHECK:STDOUT:     %assoc0: %I4.assoc_type = assoc_entity element0, @I4.%T4 [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %T5: type = assoc_const_decl @T5 [concrete] {
-// CHECK:STDOUT:     %assoc1: %I4.assoc_type = assoc_entity element1, @I4.%T5 [concrete = constants.%assoc1]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %T6: type = assoc_const_decl @T6 [concrete] {
-// CHECK:STDOUT:     %assoc2: %I4.assoc_type = assoc_entity element2, @I4.%T6 [concrete = constants.%assoc2]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .T4 = @T4.%assoc0
-// CHECK:STDOUT:   .T5 = @T5.%assoc1
-// CHECK:STDOUT:   .T6 = @T6.%assoc2
-// CHECK:STDOUT:   witness = (%T4, %T5, %T6)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @T4(@I4.%Self: %I4.type) {
-// CHECK:STDOUT:   assoc_const T4:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @T5(@I4.%Self: %I4.type) {
-// CHECK:STDOUT:   assoc_const T5:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @T6(@I4.%Self: %I4.type) {
-// CHECK:STDOUT:   assoc_const T6:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.de506c.1: %.loc17_7.2 as %.loc17_15;
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.de506c.2: %.loc27_7.2 as %.loc27_15 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = <error>
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T4(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T5(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T6(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T4(constants.%I4.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T5(constants.%I4.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @T6(constants.%I4.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_missing_on_definition.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %K.type: type = facet_type <@K> [concrete]
-// CHECK:STDOUT:   %Self: %K.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %K.assoc_type: type = assoc_entity_type @K [concrete]
-// CHECK:STDOUT:   %assoc0: %K.assoc_type = assoc_entity element0, @K.%V [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %K.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %K.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @K [symbolic_self]
-// CHECK:STDOUT:   %K.facet: %K.type = facet_value %.Self.as_type, (%K.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %K.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %K_where.type: type = facet_type <@K where %impl.elem0 = %empty_struct_type> [concrete]
-// CHECK:STDOUT:   %K.impl_witness.3ea: <witness> = impl_witness file.%K.impl_witness_table.loc5 [concrete]
-// CHECK:STDOUT:   %K.impl_witness.3f0: <witness> = impl_witness file.%K.impl_witness_table.loc17 [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .K = %K.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %K.decl: type = interface_decl @K [concrete = constants.%K.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl.16d [concrete] {} {
-// CHECK:STDOUT:     %.loc5_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc5_7.2: type = converted %.loc5_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %K.ref: type = name_ref K, file.%K.decl [concrete = constants.%K.type]
-// CHECK:STDOUT:     %.Self: %K.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref: %K.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %V.ref: %K.assoc_type = name_ref V, @V.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc5_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: type = impl_witness_access constants.%K.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc5_26.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc5_26.2: type = converted %.loc5_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.loc5_14: type = where_expr %.Self [concrete = constants.%K_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc5_26.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %K.impl_witness_table.loc5 = impl_witness_table (%impl_witness_assoc_constant), @impl.16d [concrete]
-// CHECK:STDOUT:   %K.impl_witness.loc5: <witness> = impl_witness %K.impl_witness_table.loc5 [concrete = constants.%K.impl_witness.3ea]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   impl_decl @impl.4b0 [concrete] {} {
-// CHECK:STDOUT:     %.loc17_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc17_7.2: type = converted %.loc17_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %K.ref: type = name_ref K, file.%K.decl [concrete = constants.%K.type]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %K.impl_witness_table.loc17 = impl_witness_table (<error>), @impl.4b0 [concrete]
-// CHECK:STDOUT:   %K.impl_witness.loc17: <witness> = impl_witness %K.impl_witness_table.loc17 [concrete = constants.%K.impl_witness.3f0]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @K {
-// CHECK:STDOUT:   %Self: %K.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %V: type = assoc_const_decl @V [concrete] {
-// CHECK:STDOUT:     %assoc0: %K.assoc_type = assoc_entity element0, @K.%V [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .V = @V.%assoc0
-// CHECK:STDOUT:   witness = (%V)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @V(@K.%Self: %K.type) {
-// CHECK:STDOUT:   assoc_const V:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.16d: %.loc5_7.2 as %.loc5_14;
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.4b0: %.loc17_7.2 as %K.ref {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%K.impl_witness.loc17
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @V(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @V(constants.%K.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_two_different.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %L.type: type = facet_type <@L> [concrete]
-// CHECK:STDOUT:   %Self: %L.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %L.assoc_type: type = assoc_entity_type @L [concrete]
-// CHECK:STDOUT:   %assoc0: %L.assoc_type = assoc_entity element0, @L.%W [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %L.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %L.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @L [symbolic_self]
-// CHECK:STDOUT:   %L.facet: %L.type = facet_value %.Self.as_type, (%L.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %L.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %L_where.type: type = facet_type <@L where %impl.elem0 = %empty_tuple.type and %impl.elem0 = %empty_struct_type> [concrete]
-// CHECK:STDOUT:   %L.impl_witness: <witness> = impl_witness file.%L.impl_witness_table [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .L = %L.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %L.decl: type = interface_decl @L [concrete = constants.%L.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %L.ref: type = name_ref L, file.%L.decl [concrete = constants.%L.type]
-// CHECK:STDOUT:     %.Self: %L.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc9_20: %L.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %W.ref.loc9_20: %L.assoc_type = name_ref W, @W.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc9_20: type = facet_access_type %.Self.ref.loc9_20 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc9_20: type = converted %.Self.ref.loc9_20, %.Self.as_type.loc9_20 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc9_20: type = impl_witness_access constants.%L.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc9_26.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc9_26.2: type = converted %.loc9_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.Self.ref.loc9_32: %L.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %W.ref.loc9_32: %L.assoc_type = name_ref W, @W.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc9_32: type = facet_access_type %.Self.ref.loc9_32 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc9_32: type = converted %.Self.ref.loc9_32, %.Self.as_type.loc9_32 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc9_32: type = impl_witness_access constants.%L.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc9_38.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc9_38.2: type = converted %.loc9_38.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %.loc9_14: type = where_expr %.Self [concrete = constants.%L_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_20, %.loc9_26.2
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_32, %.loc9_38.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %L.impl_witness_table = impl_witness_table (<error>), @impl [concrete]
-// CHECK:STDOUT:   %L.impl_witness: <witness> = impl_witness %L.impl_witness_table [concrete = constants.%L.impl_witness]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @L {
-// CHECK:STDOUT:   %Self: %L.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %W: type = assoc_const_decl @W [concrete] {
-// CHECK:STDOUT:     %assoc0: %L.assoc_type = assoc_entity element0, @L.%W [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .W = @W.%assoc0
-// CHECK:STDOUT:   witness = (%W)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @W(@L.%Self: %L.type) {
-// CHECK:STDOUT:   assoc_const W:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc9_7.2 as %.loc9_14 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%L.impl_witness
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @W(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @W(constants.%L.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_two_different_first_bad.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %L2.type: type = facet_type <@L2> [concrete]
-// CHECK:STDOUT:   %Self: %L2.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %L2.assoc_type: type = assoc_entity_type @L2 [concrete]
-// CHECK:STDOUT:   %assoc0: %L2.assoc_type = assoc_entity element0, @L2.%W2 [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %L2.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %L2.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @L2 [symbolic_self]
-// CHECK:STDOUT:   %L2.facet: %L2.type = facet_value %.Self.as_type, (%L2.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %L2.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .L2 = %L2.decl
-// CHECK:STDOUT:     .BAD5 = <poisoned>
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %L2.decl: type = interface_decl @L2 [concrete = constants.%L2.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %L2.ref: type = name_ref L2, file.%L2.decl [concrete = constants.%L2.type]
-// CHECK:STDOUT:     %.Self: %L2.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc9_21: %L2.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %W2.ref.loc9_21: %L2.assoc_type = name_ref W2, @W2.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc9_21: type = facet_access_type %.Self.ref.loc9_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc9_21: type = converted %.Self.ref.loc9_21, %.Self.as_type.loc9_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc9_21: type = impl_witness_access constants.%L2.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %BAD5.ref: <error> = name_ref BAD5, <error> [concrete = <error>]
-// CHECK:STDOUT:     %.Self.ref.loc9_36: %L2.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %W2.ref.loc9_36: %L2.assoc_type = name_ref W2, @W2.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc9_36: type = facet_access_type %.Self.ref.loc9_36 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc9_36: type = converted %.Self.ref.loc9_36, %.Self.as_type.loc9_36 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc9_36: type = impl_witness_access constants.%L2.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc9_43.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc9_43.2: type = converted %.loc9_43.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %.loc9_15: type = where_expr %.Self [concrete = <error>] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_21, <error>
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_36, %.loc9_43.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @L2 {
-// CHECK:STDOUT:   %Self: %L2.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %W2: type = assoc_const_decl @W2 [concrete] {
-// CHECK:STDOUT:     %assoc0: %L2.assoc_type = assoc_entity element0, @L2.%W2 [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .W2 = @W2.%assoc0
-// CHECK:STDOUT:   witness = (%W2)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @W2(@L2.%Self: %L2.type) {
-// CHECK:STDOUT:   assoc_const W2:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc9_7.2 as %.loc9_15 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = <error>
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @W2(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @W2(constants.%L2.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_two_different_second_bad.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %L3.type: type = facet_type <@L3> [concrete]
-// CHECK:STDOUT:   %Self: %L3.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %L3.assoc_type: type = assoc_entity_type @L3 [concrete]
-// CHECK:STDOUT:   %assoc0: %L3.assoc_type = assoc_entity element0, @L3.%W3 [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %L3.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %L3.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @L3 [symbolic_self]
-// CHECK:STDOUT:   %L3.facet: %L3.type = facet_value %.Self.as_type, (%L3.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %L3.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .L3 = %L3.decl
-// CHECK:STDOUT:     .BAD6 = <poisoned>
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %L3.decl: type = interface_decl @L3 [concrete = constants.%L3.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc9_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc9_7.2: type = converted %.loc9_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %L3.ref: type = name_ref L3, file.%L3.decl [concrete = constants.%L3.type]
-// CHECK:STDOUT:     %.Self: %L3.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc9_21: %L3.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %W3.ref.loc9_21: %L3.assoc_type = name_ref W3, @W3.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc9_21: type = facet_access_type %.Self.ref.loc9_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc9_21: type = converted %.Self.ref.loc9_21, %.Self.as_type.loc9_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc9_21: type = impl_witness_access constants.%L3.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc9_28.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc9_28.2: type = converted %.loc9_28.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.Self.ref.loc9_34: %L3.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %W3.ref.loc9_34: %L3.assoc_type = name_ref W3, @W3.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc9_34: type = facet_access_type %.Self.ref.loc9_34 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc9_34: type = converted %.Self.ref.loc9_34, %.Self.as_type.loc9_34 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc9_34: type = impl_witness_access constants.%L3.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %BAD6.ref: <error> = name_ref BAD6, <error> [concrete = <error>]
-// CHECK:STDOUT:     %.loc9_15: type = where_expr %.Self [concrete = <error>] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_21, %.loc9_28.2
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc9_34, <error>
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @L3 {
-// CHECK:STDOUT:   %Self: %L3.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %W3: type = assoc_const_decl @W3 [concrete] {
-// CHECK:STDOUT:     %assoc0: %L3.assoc_type = assoc_entity element0, @L3.%W3 [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .W3 = @W3.%assoc0
-// CHECK:STDOUT:   witness = (%W3)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @W3(@L3.%Self: %L3.type) {
-// CHECK:STDOUT:   assoc_const W3:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc9_7.2 as %.loc9_15 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = <error>
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @W3(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @W3(constants.%L3.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_two_different_both_bad.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %L4.type: type = facet_type <@L4> [concrete]
-// CHECK:STDOUT:   %Self: %L4.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %L4.assoc_type: type = assoc_entity_type @L4 [concrete]
-// CHECK:STDOUT:   %assoc0: %L4.assoc_type = assoc_entity element0, @L4.%W4 [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %L4.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %L4.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @L4 [symbolic_self]
-// CHECK:STDOUT:   %L4.facet: %L4.type = facet_value %.Self.as_type, (%L4.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %L4.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .L4 = %L4.decl
-// CHECK:STDOUT:     .BAD7 = <poisoned>
-// CHECK:STDOUT:     .BAD8 = <poisoned>
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %L4.decl: type = interface_decl @L4 [concrete = constants.%L4.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc13_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc13_7.2: type = converted %.loc13_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %L4.ref: type = name_ref L4, file.%L4.decl [concrete = constants.%L4.type]
-// CHECK:STDOUT:     %.Self: %L4.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc13_21: %L4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %W4.ref.loc13_21: %L4.assoc_type = name_ref W4, @W4.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc13_21: type = facet_access_type %.Self.ref.loc13_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc13_21: type = converted %.Self.ref.loc13_21, %.Self.as_type.loc13_21 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc13_21: type = impl_witness_access constants.%L4.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %BAD7.ref: <error> = name_ref BAD7, <error> [concrete = <error>]
-// CHECK:STDOUT:     %.Self.ref.loc13_36: %L4.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %W4.ref.loc13_36: %L4.assoc_type = name_ref W4, @W4.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc13_36: type = facet_access_type %.Self.ref.loc13_36 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc13_36: type = converted %.Self.ref.loc13_36, %.Self.as_type.loc13_36 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc13_36: type = impl_witness_access constants.%L4.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %BAD8.ref: <error> = name_ref BAD8, <error> [concrete = <error>]
-// CHECK:STDOUT:     %.loc13_15: type = where_expr %.Self [concrete = <error>] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc13_21, <error>
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc13_36, <error>
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @L4 {
-// CHECK:STDOUT:   %Self: %L4.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %W4: type = assoc_const_decl @W4 [concrete] {
-// CHECK:STDOUT:     %assoc0: %L4.assoc_type = assoc_entity element0, @L4.%W4 [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .W4 = @W4.%assoc0
-// CHECK:STDOUT:   witness = (%W4)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @W4(@L4.%Self: %L4.type) {
-// CHECK:STDOUT:   assoc_const W4:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc13_7.2 as %.loc13_15 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = <error>
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @W4(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @W4(constants.%L4.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- repeated.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %M.type: type = facet_type <@M> [concrete]
-// CHECK:STDOUT:   %Self: %M.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %M.assoc_type: type = assoc_entity_type @M [concrete]
-// CHECK:STDOUT:   %assoc0: %M.assoc_type = assoc_entity element0, @M.%X [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %.Self: %M.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %M.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @M [symbolic_self]
-// CHECK:STDOUT:   %M.facet: %M.type = facet_value %.Self.as_type, (%M.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: type = impl_witness_access %M.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %M_where.type: type = facet_type <@M where %impl.elem0 = %empty_struct_type> [concrete]
-// CHECK:STDOUT:   %M.impl_witness: <witness> = impl_witness file.%M.impl_witness_table [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .M = %M.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %M.decl: type = interface_decl @M [concrete = constants.%M.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc5_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc5_7.2: type = converted %.loc5_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %M.ref: type = name_ref M, file.%M.decl [concrete = constants.%M.type]
-// CHECK:STDOUT:     %.Self: %M.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref.loc5_20: %M.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %X.ref.loc5_20: %M.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc5_20: type = facet_access_type %.Self.ref.loc5_20 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc5_20: type = converted %.Self.ref.loc5_20, %.Self.as_type.loc5_20 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc5_20: type = impl_witness_access constants.%M.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc5_26.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc5_26.2: type = converted %.loc5_26.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.Self.ref.loc5_32: %M.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %X.ref.loc5_32: %M.assoc_type = name_ref X, @X.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type.loc5_32: type = facet_access_type %.Self.ref.loc5_32 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc5_32: type = converted %.Self.ref.loc5_32, %.Self.as_type.loc5_32 [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0.loc5_32: type = impl_witness_access constants.%M.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc5_38.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc5_38.2: type = converted %.loc5_38.1, constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:     %.loc5_14: type = where_expr %.Self [concrete = constants.%M_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc5_20, %.loc5_26.2
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0.loc5_32, %.loc5_38.2
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %M.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl [concrete]
-// CHECK:STDOUT:   %M.impl_witness: <witness> = impl_witness %M.impl_witness_table [concrete = constants.%M.impl_witness]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: type = impl_witness_assoc_constant constants.%empty_struct_type [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @M {
-// CHECK:STDOUT:   %Self: %M.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %X: type = assoc_const_decl @X [concrete] {
-// CHECK:STDOUT:     %assoc0: %M.assoc_type = assoc_entity element0, @M.%X [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .X = @X.%assoc0
-// CHECK:STDOUT:   witness = (%X)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @X(@M.%Self: %M.type) {
-// CHECK:STDOUT:   assoc_const X:! type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc5_7.2 as %.loc5_14 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%M.impl_witness
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @X(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @X(constants.%M.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- non-type.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %N.type: type = facet_type <@N> [concrete]
-// CHECK:STDOUT:   %Self: %N.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %struct_type.a.225: type = struct_type {.a: %empty_struct_type} [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %N.assoc_type: type = assoc_entity_type @N [concrete]
-// CHECK:STDOUT:   %assoc0: %N.assoc_type = assoc_entity element0, @N.%Y [concrete]
-// CHECK:STDOUT:   %.Self: %N.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %N.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @N [symbolic_self]
-// CHECK:STDOUT:   %N.facet: %N.type = facet_value %.Self.as_type, (%N.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: %struct_type.a.225 = impl_witness_access %N.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %empty_struct: %empty_struct_type = struct_value () [concrete]
-// CHECK:STDOUT:   %struct: %struct_type.a.225 = struct_value (%empty_struct) [concrete]
-// CHECK:STDOUT:   %N_where.type: type = facet_type <@N where %impl.elem0 = %struct> [concrete]
-// CHECK:STDOUT:   %N.impl_witness: <witness> = impl_witness file.%N.impl_witness_table [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .N = %N.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %N.decl: type = interface_decl @N [concrete = constants.%N.type] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc7_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc7_7.2: type = converted %.loc7_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %N.ref: type = name_ref N, file.%N.decl [concrete = constants.%N.type]
-// CHECK:STDOUT:     %.Self: %N.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref: %N.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %Y.ref: %N.assoc_type = name_ref Y, @Y.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc7_20: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: %struct_type.a.225 = impl_witness_access constants.%N.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %.loc7_32: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:     %.loc7_33.1: %struct_type.a.225 = struct_literal (%.loc7_32)
-// CHECK:STDOUT:     %empty_struct: %empty_struct_type = struct_value () [concrete = constants.%empty_struct]
-// CHECK:STDOUT:     %.loc7_33.2: %empty_struct_type = converted %.loc7_32, %empty_struct [concrete = constants.%empty_struct]
-// CHECK:STDOUT:     %struct: %struct_type.a.225 = struct_value (%.loc7_33.2) [concrete = constants.%struct]
-// CHECK:STDOUT:     %.loc7_33.3: %struct_type.a.225 = converted %.loc7_33.1, %struct [concrete = constants.%struct]
-// CHECK:STDOUT:     %.loc7_14: type = where_expr %.Self [concrete = constants.%N_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %.loc7_33.3
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %N.impl_witness_table = impl_witness_table (%impl_witness_assoc_constant), @impl [concrete]
-// CHECK:STDOUT:   %N.impl_witness: <witness> = impl_witness %N.impl_witness_table [concrete = constants.%N.impl_witness]
-// CHECK:STDOUT:   %impl_witness_assoc_constant: %struct_type.a.225 = impl_witness_assoc_constant constants.%struct [concrete = constants.%struct]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @N {
-// CHECK:STDOUT:   %Self: %N.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %Y: %struct_type.a.225 = assoc_const_decl @Y [concrete] {
-// CHECK:STDOUT:     %assoc0: %N.assoc_type = assoc_entity element0, @N.%Y [concrete = constants.%assoc0]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .Y = @Y.%assoc0
-// CHECK:STDOUT:   witness = (%Y)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic assoc_const @Y(@N.%Self: %N.type) {
-// CHECK:STDOUT:   assoc_const Y:! %struct_type.a.225;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc7_7.2 as %.loc7_14 {
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   witness = file.%N.impl_witness
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @Y(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @Y(constants.%N.facet) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_where_rewrite_function.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %IF.type: type = facet_type <@IF> [concrete]
-// CHECK:STDOUT:   %Self: %IF.type = bind_symbolic_name Self, 0 [symbolic]
-// CHECK:STDOUT:   %F.type.496: type = fn_type @F.1 [concrete]
-// CHECK:STDOUT:   %F.1de: %F.type.496 = struct_value () [concrete]
-// CHECK:STDOUT:   %IF.assoc_type: type = assoc_entity_type @IF [concrete]
-// CHECK:STDOUT:   %assoc0: %IF.assoc_type = assoc_entity element0, @IF.%F.decl [concrete]
-// CHECK:STDOUT:   %CD: type = class_type @CD [concrete]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
-// CHECK:STDOUT:   %.Self: %IF.type = bind_symbolic_name .Self [symbolic_self]
-// CHECK:STDOUT:   %.Self.as_type: type = facet_access_type %.Self [symbolic_self]
-// CHECK:STDOUT:   %IF.lookup_impl_witness: <witness> = lookup_impl_witness %.Self, @IF [symbolic_self]
-// CHECK:STDOUT:   %IF.facet.01b: %IF.type = facet_value %.Self.as_type, (%IF.lookup_impl_witness) [symbolic_self]
-// CHECK:STDOUT:   %.c5b: type = fn_type_with_self_type %F.type.496, %IF.facet.01b [symbolic_self]
-// CHECK:STDOUT:   %impl.elem0: %.c5b = impl_witness_access %IF.lookup_impl_witness, element0 [symbolic_self]
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
-// CHECK:STDOUT:   %IF_where.type: type = facet_type <@IF where %impl.elem0 = %int_0> [concrete]
-// CHECK:STDOUT:   %IF.impl_witness: <witness> = impl_witness file.%IF.impl_witness_table [concrete]
-// CHECK:STDOUT:   %F.type.f56: type = fn_type @F.2 [concrete]
-// CHECK:STDOUT:   %F.fae: %F.type.f56 = struct_value () [concrete]
-// CHECK:STDOUT:   %IF.facet.60c: %IF.type = facet_value %CD, (%IF.impl_witness) [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .IF = %IF.decl
-// CHECK:STDOUT:     .CD = %CD.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %IF.decl: type = interface_decl @IF [concrete = constants.%IF.type] {} {}
-// CHECK:STDOUT:   %CD.decl: type = class_decl @CD [concrete = constants.%CD] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %CD.ref: type = name_ref CD, file.%CD.decl [concrete = constants.%CD]
-// CHECK:STDOUT:     %IF.ref: type = name_ref IF, file.%IF.decl [concrete = constants.%IF.type]
-// CHECK:STDOUT:     %.Self: %IF.type = bind_symbolic_name .Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %.Self.ref: %IF.type = name_ref .Self, %.Self [symbolic_self = constants.%.Self]
-// CHECK:STDOUT:     %F.ref: %IF.assoc_type = name_ref F, @IF.%assoc0 [concrete = constants.%assoc0]
-// CHECK:STDOUT:     %.Self.as_type: type = facet_access_type %.Self.ref [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %.loc11_21: type = converted %.Self.ref, %.Self.as_type [symbolic_self = constants.%.Self.as_type]
-// CHECK:STDOUT:     %impl.elem0: %.c5b = impl_witness_access constants.%IF.lookup_impl_witness, element0 [symbolic_self = constants.%impl.elem0]
-// CHECK:STDOUT:     %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
-// CHECK:STDOUT:     %.loc11_15: type = where_expr %.Self [concrete = constants.%IF_where.type] {
-// CHECK:STDOUT:       requirement_rewrite %impl.elem0, %int_0
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %IF.impl_witness_table = impl_witness_table (@impl.%F.decl), @impl [concrete]
-// CHECK:STDOUT:   %IF.impl_witness: <witness> = impl_witness %IF.impl_witness_table [concrete = constants.%IF.impl_witness]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: interface @IF {
-// CHECK:STDOUT:   %Self: %IF.type = bind_symbolic_name Self, 0 [symbolic = constants.%Self]
-// CHECK:STDOUT:   %F.decl: %F.type.496 = fn_decl @F.1 [concrete = constants.%F.1de] {} {}
-// CHECK:STDOUT:   %assoc0: %IF.assoc_type = assoc_entity element0, %F.decl [concrete = constants.%assoc0]
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = %Self
-// CHECK:STDOUT:   .F = %assoc0
-// CHECK:STDOUT:   witness = (%F.decl)
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %CD.ref as %.loc11_15 {
-// CHECK:STDOUT:   %F.decl: %F.type.f56 = fn_decl @F.2 [concrete = constants.%F.fae] {} {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .F = %F.decl
-// CHECK:STDOUT:   witness = file.%IF.impl_witness
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: class @CD {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%CD
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @F.1(@IF.%Self: %IF.type) {
-// CHECK:STDOUT:   fn();
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @F.2() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   return
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @F.1(constants.%Self) {}
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @F.1(constants.%IF.facet.60c) {}
-// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/impl/no_prelude/self_in_class.carbon b/toolchain/check/testdata/impl/self_in_class.carbon
similarity index 97%
rename from toolchain/check/testdata/impl/no_prelude/self_in_class.carbon
rename to toolchain/check/testdata/impl/self_in_class.carbon
index 995749ef93da..29ea9dadc042 100644
--- a/toolchain/check/testdata/impl/no_prelude/self_in_class.carbon
+++ b/toolchain/check/testdata/impl/self_in_class.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/self_in_class.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/self_in_class.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/self_in_class.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/self_in_class.carbon
 
 interface DefaultConstructible {
   fn Make() -> Self;
diff --git a/toolchain/check/testdata/impl/no_prelude/self_in_signature.carbon b/toolchain/check/testdata/impl/self_in_signature.carbon
similarity index 99%
rename from toolchain/check/testdata/impl/no_prelude/self_in_signature.carbon
rename to toolchain/check/testdata/impl/self_in_signature.carbon
index 9a7432f90e50..00dc87c409e1 100644
--- a/toolchain/check/testdata/impl/no_prelude/self_in_signature.carbon
+++ b/toolchain/check/testdata/impl/self_in_signature.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/self_in_signature.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/self_in_signature.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/self_in_signature.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/self_in_signature.carbon
 
 interface UseSelf {
   fn F[self: Self](x: Self) -> Self;
diff --git a/toolchain/check/testdata/impl/no_prelude/todo_impl_with_unrelated_fn.carbon b/toolchain/check/testdata/impl/todo_impl_with_unrelated_fn.carbon
similarity index 95%
rename from toolchain/check/testdata/impl/no_prelude/todo_impl_with_unrelated_fn.carbon
rename to toolchain/check/testdata/impl/todo_impl_with_unrelated_fn.carbon
index 8375d30a4e8f..4ffa0f0d5204 100644
--- a/toolchain/check/testdata/impl/no_prelude/todo_impl_with_unrelated_fn.carbon
+++ b/toolchain/check/testdata/impl/todo_impl_with_unrelated_fn.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/no_prelude/todo_impl_with_unrelated_fn.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/todo_impl_with_unrelated_fn.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/no_prelude/todo_impl_with_unrelated_fn.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/todo_impl_with_unrelated_fn.carbon
 
 interface A {
   fn B();
diff --git a/toolchain/check/testdata/interface/no_prelude/as_type.carbon b/toolchain/check/testdata/interface/as_type.carbon
similarity index 91%
rename from toolchain/check/testdata/interface/no_prelude/as_type.carbon
rename to toolchain/check/testdata/interface/as_type.carbon
index d95da898fc63..093b5c2c14f8 100644
--- a/toolchain/check/testdata/interface/no_prelude/as_type.carbon
+++ b/toolchain/check/testdata/interface/as_type.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/as_type.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/as_type.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/as_type.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/as_type.carbon
 
 interface Empty {}
 
diff --git a/toolchain/check/testdata/interface/no_prelude/assoc_const_in_generic.carbon b/toolchain/check/testdata/interface/assoc_const_in_generic.carbon
similarity index 98%
rename from toolchain/check/testdata/interface/no_prelude/assoc_const_in_generic.carbon
rename to toolchain/check/testdata/interface/assoc_const_in_generic.carbon
index 88874fcdd1d4..0802d98a59f7 100644
--- a/toolchain/check/testdata/interface/no_prelude/assoc_const_in_generic.carbon
+++ b/toolchain/check/testdata/interface/assoc_const_in_generic.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/assoc_const_in_generic.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/assoc_const_in_generic.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/assoc_const_in_generic.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/assoc_const_in_generic.carbon
 
 interface I(T:! type) {
   fn F(U:! type) -> U;
diff --git a/toolchain/check/testdata/interface/no_prelude/basic.carbon b/toolchain/check/testdata/interface/basic.carbon
similarity index 94%
rename from toolchain/check/testdata/interface/no_prelude/basic.carbon
rename to toolchain/check/testdata/interface/basic.carbon
index a66189f133b0..9d312a942949 100644
--- a/toolchain/check/testdata/interface/no_prelude/basic.carbon
+++ b/toolchain/check/testdata/interface/basic.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/basic.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/basic.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/basic.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/basic.carbon
 
 interface Empty {
 }
diff --git a/toolchain/check/testdata/interface/no_prelude/export_name.carbon b/toolchain/check/testdata/interface/export_name.carbon
similarity index 95%
rename from toolchain/check/testdata/interface/no_prelude/export_name.carbon
rename to toolchain/check/testdata/interface/export_name.carbon
index ff4bd6b5f392..077e471e9895 100644
--- a/toolchain/check/testdata/interface/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/interface/export_name.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/export_name.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/export_name.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/export_name.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/export_name.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon b/toolchain/check/testdata/interface/fail_add_member_outside_definition.carbon
similarity index 96%
rename from toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon
rename to toolchain/check/testdata/interface/fail_add_member_outside_definition.carbon
index c76b0f7eab2b..8df965c316a2 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon
+++ b/toolchain/check/testdata/interface/fail_add_member_outside_definition.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_add_member_outside_definition.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_add_member_outside_definition.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_add_member_outside_definition.carbon
 
 interface Interface { }
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_alias.carbon b/toolchain/check/testdata/interface/fail_assoc_const_alias.carbon
similarity index 99%
rename from toolchain/check/testdata/interface/no_prelude/fail_assoc_const_alias.carbon
rename to toolchain/check/testdata/interface/fail_assoc_const_alias.carbon
index baa0ffbe657a..60ba3c0b83f2 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_alias.carbon
+++ b/toolchain/check/testdata/interface/fail_assoc_const_alias.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_alias.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_assoc_const_alias.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_alias.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_assoc_const_alias.carbon
 
 // --- core.carbon
 package Core;
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon b/toolchain/check/testdata/interface/fail_assoc_const_not_binding.carbon
similarity index 95%
rename from toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon
rename to toolchain/check/testdata/interface/fail_assoc_const_not_binding.carbon
index 8259fc98ed7c..bbf6a2767ac1 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon
+++ b/toolchain/check/testdata/interface/fail_assoc_const_not_binding.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_assoc_const_not_binding.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_binding.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_assoc_const_not_binding.carbon
 
 // --- fail_tuple_pattern.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon b/toolchain/check/testdata/interface/fail_assoc_const_not_constant.carbon
similarity index 81%
rename from toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon
rename to toolchain/check/testdata/interface/fail_assoc_const_not_constant.carbon
index 208fcaffc2d4..d5d6b319b3d9 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon
+++ b/toolchain/check/testdata/interface/fail_assoc_const_not_constant.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_assoc_const_not_constant.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_not_constant.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_assoc_const_not_constant.carbon
 
 interface I {
   // CHECK:STDERR: fail_assoc_const_not_constant.carbon:[[@LINE+4]]:7: error: found runtime binding pattern in associated constant declaration; expected a `:!` binding [ExpectedSymbolicBindingInAssociatedConstant]
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon b/toolchain/check/testdata/interface/fail_assoc_const_template.carbon
similarity index 90%
rename from toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon
rename to toolchain/check/testdata/interface/fail_assoc_const_template.carbon
index 348251d9da86..9ddb22b537ea 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon
+++ b/toolchain/check/testdata/interface/fail_assoc_const_template.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_assoc_const_template.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_const_template.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_assoc_const_template.carbon
 
 interface I {
   // CHECK:STDERR: fail_assoc_const_template.carbon:[[@LINE+4]]:20: error: associated constant has `template` binding [TemplateBindingInAssociatedConstantDecl]
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_assoc_fn_invalid_use.carbon b/toolchain/check/testdata/interface/fail_assoc_fn_invalid_use.carbon
similarity index 96%
rename from toolchain/check/testdata/interface/no_prelude/fail_assoc_fn_invalid_use.carbon
rename to toolchain/check/testdata/interface/fail_assoc_fn_invalid_use.carbon
index d76ed1bce343..ae5bda4ee31c 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_assoc_fn_invalid_use.carbon
+++ b/toolchain/check/testdata/interface/fail_assoc_fn_invalid_use.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_fn_invalid_use.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_assoc_fn_invalid_use.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_assoc_fn_invalid_use.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_assoc_fn_invalid_use.carbon
 
 // --- fail_member_access.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon b/toolchain/check/testdata/interface/fail_definition_imported.carbon
similarity index 92%
rename from toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon
rename to toolchain/check/testdata/interface/fail_definition_imported.carbon
index bac5c652d14e..5a6884247e43 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon
+++ b/toolchain/check/testdata/interface/fail_definition_imported.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_definition_imported.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_definition_imported.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_definition_imported.carbon
 
 // --- a.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon b/toolchain/check/testdata/interface/fail_duplicate.carbon
similarity index 98%
rename from toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon
rename to toolchain/check/testdata/interface/fail_duplicate.carbon
index b9c7a12c7471..be196fb46535 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon
+++ b/toolchain/check/testdata/interface/fail_duplicate.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_duplicate.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_duplicate.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_duplicate.carbon
 
 // --- fail_redefine_without_dependents.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon b/toolchain/check/testdata/interface/fail_generic_redeclaration.carbon
similarity index 97%
rename from toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon
rename to toolchain/check/testdata/interface/fail_generic_redeclaration.carbon
index b45b11ca80d7..f8f2ca46ad28 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon
+++ b/toolchain/check/testdata/interface/fail_generic_redeclaration.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_generic_redeclaration.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_generic_redeclaration.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_generic_redeclaration.carbon
 
 interface NotGeneric;
 // CHECK:STDERR: fail_generic_redeclaration.carbon:[[@LINE+7]]:1: error: redeclaration differs because of parameter list [RedeclParamListDiffers]
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_incomplete_type.carbon b/toolchain/check/testdata/interface/fail_incomplete_type.carbon
similarity index 92%
rename from toolchain/check/testdata/interface/no_prelude/fail_incomplete_type.carbon
rename to toolchain/check/testdata/interface/fail_incomplete_type.carbon
index 6a5f94a4b57b..96937142763a 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_incomplete_type.carbon
+++ b/toolchain/check/testdata/interface/fail_incomplete_type.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_incomplete_type.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_incomplete_type.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_incomplete_type.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_incomplete_type.carbon
 
 class C;
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon b/toolchain/check/testdata/interface/fail_lookup_in_type_type.carbon
similarity index 93%
rename from toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon
rename to toolchain/check/testdata/interface/fail_lookup_in_type_type.carbon
index c9849e8c0df7..b22c536c7127 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon
+++ b/toolchain/check/testdata/interface/fail_lookup_in_type_type.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_lookup_in_type_type.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_lookup_in_type_type.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_lookup_in_type_type.carbon
 
 // --- fail_lookup_in_type.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon b/toolchain/check/testdata/interface/fail_lookup_undefined.carbon
similarity index 96%
rename from toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon
rename to toolchain/check/testdata/interface/fail_lookup_undefined.carbon
index a5c01c645650..c099175eee01 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon
+++ b/toolchain/check/testdata/interface/fail_lookup_undefined.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_lookup_undefined.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_lookup_undefined.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_lookup_undefined.carbon
 
 interface Undefined;
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/interface/fail_modifiers.carbon
similarity index 98%
rename from toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon
rename to toolchain/check/testdata/interface/fail_modifiers.carbon
index 8e312d756acd..5963637ad215 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/interface/fail_modifiers.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_modifiers.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_modifiers.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_modifiers.carbon
 
 // --- fail_abstract.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon b/toolchain/check/testdata/interface/fail_redeclare_member.carbon
similarity index 93%
rename from toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon
rename to toolchain/check/testdata/interface/fail_redeclare_member.carbon
index 94d343e31e99..ab551503bb96 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon
+++ b/toolchain/check/testdata/interface/fail_redeclare_member.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_redeclare_member.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_redeclare_member.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_redeclare_member.carbon
 
 interface Interface {
   fn F();
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon b/toolchain/check/testdata/interface/fail_todo_generic_default_fn.carbon
similarity index 98%
rename from toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon
rename to toolchain/check/testdata/interface/fail_todo_generic_default_fn.carbon
index 479eba87c96e..d662c553c175 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon
+++ b/toolchain/check/testdata/interface/fail_todo_generic_default_fn.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_todo_generic_default_fn.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_todo_generic_default_fn.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_todo_generic_default_fn.carbon
 
 interface I(T:! type) {
   // TODO: Use `default` here.
diff --git a/toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon b/toolchain/check/testdata/interface/fail_todo_modifiers.carbon
similarity index 94%
rename from toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon
rename to toolchain/check/testdata/interface/fail_todo_modifiers.carbon
index 6fbf7cb2371a..e27c04f49c79 100644
--- a/toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon
+++ b/toolchain/check/testdata/interface/fail_todo_modifiers.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/fail_todo_modifiers.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/fail_todo_modifiers.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/fail_todo_modifiers.carbon
 
 interface Modifiers {
   // CHECK:STDERR: fail_todo_modifiers.carbon:[[@LINE+4]]:3: error: semantics TODO: `interface modifier` [SemanticsTodo]
diff --git a/toolchain/check/testdata/interface/no_prelude/generic.carbon b/toolchain/check/testdata/interface/generic.carbon
similarity index 99%
rename from toolchain/check/testdata/interface/no_prelude/generic.carbon
rename to toolchain/check/testdata/interface/generic.carbon
index 897a1fa72693..552f03bd07e3 100644
--- a/toolchain/check/testdata/interface/no_prelude/generic.carbon
+++ b/toolchain/check/testdata/interface/generic.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/generic.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/generic.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/generic.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/generic.carbon
 
 // --- generic.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/generic_binding_after_assoc_const.carbon b/toolchain/check/testdata/interface/generic_binding_after_assoc_const.carbon
similarity index 94%
rename from toolchain/check/testdata/interface/no_prelude/generic_binding_after_assoc_const.carbon
rename to toolchain/check/testdata/interface/generic_binding_after_assoc_const.carbon
index 4ffb1a4b43f3..86a3d605c593 100644
--- a/toolchain/check/testdata/interface/no_prelude/generic_binding_after_assoc_const.carbon
+++ b/toolchain/check/testdata/interface/generic_binding_after_assoc_const.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/generic_binding_after_assoc_const.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/generic_binding_after_assoc_const.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/generic_binding_after_assoc_const.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/generic_binding_after_assoc_const.carbon
 
 interface I {
   fn F(T:! type);
diff --git a/toolchain/check/testdata/interface/no_prelude/generic_import.carbon b/toolchain/check/testdata/interface/generic_import.carbon
similarity index 98%
rename from toolchain/check/testdata/interface/no_prelude/generic_import.carbon
rename to toolchain/check/testdata/interface/generic_import.carbon
index 3dcfd9cf4465..98cf38a61bd3 100644
--- a/toolchain/check/testdata/interface/no_prelude/generic_import.carbon
+++ b/toolchain/check/testdata/interface/generic_import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/generic_import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/generic_import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/generic_import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/generic_import.carbon
 
 // --- a.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon b/toolchain/check/testdata/interface/generic_vs_params.carbon
similarity index 99%
rename from toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon
rename to toolchain/check/testdata/interface/generic_vs_params.carbon
index 95c9bcbf0f49..3d1299d36cd1 100644
--- a/toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon
+++ b/toolchain/check/testdata/interface/generic_vs_params.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/generic_vs_params.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/generic_vs_params.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/generic_vs_params.carbon
 
 // --- params.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/import.carbon b/toolchain/check/testdata/interface/import.carbon
similarity index 98%
rename from toolchain/check/testdata/interface/no_prelude/import.carbon
rename to toolchain/check/testdata/interface/import.carbon
index 449801b7f06b..d1c6e6cecd1f 100644
--- a/toolchain/check/testdata/interface/no_prelude/import.carbon
+++ b/toolchain/check/testdata/interface/import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/import.carbon
 
 // --- a.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/import_access.carbon b/toolchain/check/testdata/interface/import_access.carbon
similarity index 99%
rename from toolchain/check/testdata/interface/no_prelude/import_access.carbon
rename to toolchain/check/testdata/interface/import_access.carbon
index 33abb55b4878..1a59246efca3 100644
--- a/toolchain/check/testdata/interface/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/interface/import_access.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/import_access.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/import_access.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/import_access.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/import_access.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon b/toolchain/check/testdata/interface/import_interface_decl.carbon
similarity index 95%
rename from toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon
rename to toolchain/check/testdata/interface/import_interface_decl.carbon
index 3c20968656f9..78094185966a 100644
--- a/toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon
+++ b/toolchain/check/testdata/interface/import_interface_decl.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/import_interface_decl.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/import_interface_decl.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/import_interface_decl.carbon
 
 // --- a.carbon
 library "[[@TEST_NAME]]";
diff --git a/toolchain/check/testdata/interface/no_prelude/local.carbon b/toolchain/check/testdata/interface/local.carbon
similarity index 97%
rename from toolchain/check/testdata/interface/no_prelude/local.carbon
rename to toolchain/check/testdata/interface/local.carbon
index b13b2e54915f..06d2b4db7a59 100644
--- a/toolchain/check/testdata/interface/no_prelude/local.carbon
+++ b/toolchain/check/testdata/interface/local.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/local.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/local.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/local.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/local.carbon
 
 fn F() {
   interface I {
diff --git a/toolchain/check/testdata/interface/no_prelude/name_poisoning.carbon b/toolchain/check/testdata/interface/name_poisoning.carbon
similarity index 97%
rename from toolchain/check/testdata/interface/no_prelude/name_poisoning.carbon
rename to toolchain/check/testdata/interface/name_poisoning.carbon
index 4afeb36b9410..94453e7c504b 100644
--- a/toolchain/check/testdata/interface/no_prelude/name_poisoning.carbon
+++ b/toolchain/check/testdata/interface/name_poisoning.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/name_poisoning.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/name_poisoning.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/name_poisoning.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/name_poisoning.carbon
 
 // --- no_poison.carbon
 
diff --git a/toolchain/check/testdata/interface/no_prelude/self.carbon b/toolchain/check/testdata/interface/self.carbon
similarity index 96%
rename from toolchain/check/testdata/interface/no_prelude/self.carbon
rename to toolchain/check/testdata/interface/self.carbon
index c42bcb584acf..14fd4e33cc8c 100644
--- a/toolchain/check/testdata/interface/no_prelude/self.carbon
+++ b/toolchain/check/testdata/interface/self.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/self.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/self.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/self.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/self.carbon
 
 interface UseSelf {
   fn F[self: Self]() -> Self;
diff --git a/toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon b/toolchain/check/testdata/interface/syntactic_merge.carbon
similarity index 99%
rename from toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon
rename to toolchain/check/testdata/interface/syntactic_merge.carbon
index cbbfcccf7989..8b9c55423863 100644
--- a/toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon
+++ b/toolchain/check/testdata/interface/syntactic_merge.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interface/syntactic_merge.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/no_prelude/syntactic_merge.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interface/syntactic_merge.carbon
 
 // --- basic.carbon
 
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon b/toolchain/check/testdata/interop/cpp/bad_import.carbon
similarity index 93%
rename from toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon
rename to toolchain/check/testdata/interop/cpp/bad_import.carbon
index abbb46d00ef4..192808f6b70d 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon
+++ b/toolchain/check/testdata/interop/cpp/bad_import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/bad_import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/bad_import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/bad_import.carbon
 
 // --- fail_import_cpp.carbon
 
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/class.carbon b/toolchain/check/testdata/interop/cpp/class.carbon
similarity index 99%
rename from toolchain/check/testdata/interop/cpp/no_prelude/class.carbon
rename to toolchain/check/testdata/interop/cpp/class.carbon
index 2de176984499..6b08fe3c2dd1 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/class.carbon
+++ b/toolchain/check/testdata/interop/cpp/class.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/class.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/class.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/class.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/class.carbon
 
 // ============================================================================
 // Declaration
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon b/toolchain/check/testdata/interop/cpp/cpp_diagnostics.carbon
similarity index 99%
rename from toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon
rename to toolchain/check/testdata/interop/cpp/cpp_diagnostics.carbon
index b11961ef272f..c7438c2713cb 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon
+++ b/toolchain/check/testdata/interop/cpp/cpp_diagnostics.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/cpp_diagnostics.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/cpp_diagnostics.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/cpp_diagnostics.carbon
 
 // ============================================================================
 // One error
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/cpp_namespace.carbon b/toolchain/check/testdata/interop/cpp/cpp_namespace.carbon
similarity index 97%
rename from toolchain/check/testdata/interop/cpp/no_prelude/cpp_namespace.carbon
rename to toolchain/check/testdata/interop/cpp/cpp_namespace.carbon
index bf27d8f70632..9086544445ec 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/cpp_namespace.carbon
+++ b/toolchain/check/testdata/interop/cpp/cpp_namespace.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/cpp_namespace.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/cpp_namespace.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/cpp_namespace.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/cpp_namespace.carbon
 
 // --- header.h
 
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/fail_fuzzing.carbon b/toolchain/check/testdata/interop/cpp/fail_fuzzing.carbon
similarity index 82%
rename from toolchain/check/testdata/interop/cpp/no_prelude/fail_fuzzing.carbon
rename to toolchain/check/testdata/interop/cpp/fail_fuzzing.carbon
index 41f9a07de78c..7e7652d4b255 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/fail_fuzzing.carbon
+++ b/toolchain/check/testdata/interop/cpp/fail_fuzzing.carbon
@@ -6,9 +6,9 @@
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/fail_fuzzing.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/fail_fuzzing.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/fail_fuzzing.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/fail_fuzzing.carbon
 
 // CHECK:STDERR: fail_fuzzing.carbon:[[@LINE+4]]:1: error: `Cpp` import found during fuzzing [CppInteropFuzzing]
 // CHECK:STDERR: import Cpp library "file.h";
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon b/toolchain/check/testdata/interop/cpp/file_not_found.carbon
similarity index 89%
rename from toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon
rename to toolchain/check/testdata/interop/cpp/file_not_found.carbon
index f72ab172472a..cf8b95e3d5fe 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon
+++ b/toolchain/check/testdata/interop/cpp/file_not_found.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/file_not_found.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/file_not_found.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/file_not_found.carbon
 // CHECK:STDERR: fail_cpp_file_not_found.carbon.generated.cpp_imports.h:1: error: C++:
 // CHECK:STDERR: fail_cpp_file_not_found.carbon.generated.cpp_imports.h:1:10: fatal error: 'not_found.h' file not found
 // CHECK:STDERR:     1 | #include "not_found.h"
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/function/function.carbon b/toolchain/check/testdata/interop/cpp/function/function.carbon
similarity index 98%
rename from toolchain/check/testdata/interop/cpp/no_prelude/function/function.carbon
rename to toolchain/check/testdata/interop/cpp/function/function.carbon
index f09fadc30228..c38e1698fb1c 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/function/function.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/function.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/function/function.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/function/function.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/function/function.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/function/function.carbon
 
 // ============================================================================
 // Global
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/function/inline.carbon b/toolchain/check/testdata/interop/cpp/function/inline.carbon
similarity index 95%
rename from toolchain/check/testdata/interop/cpp/no_prelude/function/inline.carbon
rename to toolchain/check/testdata/interop/cpp/function/inline.carbon
index 2343057e9f89..597dd531754d 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/function/inline.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/inline.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/function/inline.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/function/inline.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/function/inline.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/function/inline.carbon
 
 // ============================================================================
 // With definition
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/function/struct.carbon b/toolchain/check/testdata/interop/cpp/function/struct.carbon
similarity index 99%
rename from toolchain/check/testdata/interop/cpp/no_prelude/function/struct.carbon
rename to toolchain/check/testdata/interop/cpp/function/struct.carbon
index b473ce352d0f..14ab85695c6b 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/function/struct.carbon
+++ b/toolchain/check/testdata/interop/cpp/function/struct.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/function/struct.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/function/struct.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/function/struct.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/function/struct.carbon
 
 // ============================================================================
 // Forward-declared struct as parameter type
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/include.carbon b/toolchain/check/testdata/interop/cpp/include.carbon
similarity index 86%
rename from toolchain/check/testdata/interop/cpp/no_prelude/include.carbon
rename to toolchain/check/testdata/interop/cpp/include.carbon
index e9207960ecf7..ef14a2319dd7 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/include.carbon
+++ b/toolchain/check/testdata/interop/cpp/include.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/include.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/include.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/include.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/include.carbon
 
 // --- included_file.h
 
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon b/toolchain/check/testdata/interop/cpp/multiple_imports.carbon
similarity index 85%
rename from toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon
rename to toolchain/check/testdata/interop/cpp/multiple_imports.carbon
index 2da97aad3683..1bc22a17bb49 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon
+++ b/toolchain/check/testdata/interop/cpp/multiple_imports.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/multiple_imports.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/multiple_imports.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/multiple_imports.carbon
 
 // --- file1.h
 
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/namespace.carbon b/toolchain/check/testdata/interop/cpp/namespace.carbon
similarity index 98%
rename from toolchain/check/testdata/interop/cpp/no_prelude/namespace.carbon
rename to toolchain/check/testdata/interop/cpp/namespace.carbon
index 3b5073fc01cb..63040064d3ff 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/namespace.carbon
+++ b/toolchain/check/testdata/interop/cpp/namespace.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/namespace.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/namespace.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/namespace.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/namespace.carbon
 
 // ============================================================================
 // Single
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/struct.carbon b/toolchain/check/testdata/interop/cpp/struct.carbon
similarity index 99%
rename from toolchain/check/testdata/interop/cpp/no_prelude/struct.carbon
rename to toolchain/check/testdata/interop/cpp/struct.carbon
index 0c5c6943cbab..31848cd2efb1 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/struct.carbon
+++ b/toolchain/check/testdata/interop/cpp/struct.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/struct.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/struct.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/struct.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/struct.carbon
 
 // ============================================================================
 // Declaration
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/union.carbon b/toolchain/check/testdata/interop/cpp/union.carbon
similarity index 99%
rename from toolchain/check/testdata/interop/cpp/no_prelude/union.carbon
rename to toolchain/check/testdata/interop/cpp/union.carbon
index b38348a35048..5119cfede544 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/union.carbon
+++ b/toolchain/check/testdata/interop/cpp/union.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/union.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/union.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/union.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/union.carbon
 
 // ============================================================================
 // Declaration
diff --git a/toolchain/check/testdata/interop/cpp/no_prelude/unsupported_decl_type.carbon b/toolchain/check/testdata/interop/cpp/unsupported_decl_type.carbon
similarity index 91%
rename from toolchain/check/testdata/interop/cpp/no_prelude/unsupported_decl_type.carbon
rename to toolchain/check/testdata/interop/cpp/unsupported_decl_type.carbon
index abcd0e3c3482..219890367e16 100644
--- a/toolchain/check/testdata/interop/cpp/no_prelude/unsupported_decl_type.carbon
+++ b/toolchain/check/testdata/interop/cpp/unsupported_decl_type.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/no_prelude/unsupported_decl_type.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/unsupported_decl_type.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/no_prelude/unsupported_decl_type.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/unsupported_decl_type.carbon
 
 // --- unsupported_decl.h
 
diff --git a/toolchain/check/testdata/let/no_prelude/import.carbon b/toolchain/check/testdata/let/import.carbon
similarity index 97%
rename from toolchain/check/testdata/let/no_prelude/import.carbon
rename to toolchain/check/testdata/let/import.carbon
index 45ce8e4aae24..835bbf81811e 100644
--- a/toolchain/check/testdata/let/no_prelude/import.carbon
+++ b/toolchain/check/testdata/let/import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/let/no_prelude/import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/let/import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/let/no_prelude/import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/let/import.carbon
 
 // --- implicit.carbon
 
diff --git a/toolchain/check/testdata/let/no_prelude/import_access.carbon b/toolchain/check/testdata/let/import_access.carbon
similarity index 97%
rename from toolchain/check/testdata/let/no_prelude/import_access.carbon
rename to toolchain/check/testdata/let/import_access.carbon
index f2930fb81b29..f9b352bac5dc 100644
--- a/toolchain/check/testdata/let/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/let/import_access.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/let/no_prelude/import_access.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/let/import_access.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/let/no_prelude/import_access.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/let/import_access.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/operators/overloaded/index.carbon b/toolchain/check/testdata/operators/overloaded/index.carbon
index 496b8c96f740..0f283a9f0a7a 100644
--- a/toolchain/check/testdata/operators/overloaded/index.carbon
+++ b/toolchain/check/testdata/operators/overloaded/index.carbon
@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
@@ -11,646 +11,437 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/operators/overloaded/index.carbon
 
-// --- overloaded_index.carbon
+// --- core_wrong_index_with.carbon
+
+package Core library "[[@TEST_NAME]]";
+
+class IndexWith {}
+
+// --- fail_wrong_index_with.carbon
 
 library "[[@TEST_NAME]]";
 
-class C {}
-class ElementType {}
-class SubscriptType {}
+import Core library "core_wrong_index_with";
 
-impl C as Core.IndexWith(SubscriptType, ElementType) {
-  fn At[self: Self](subscript: SubscriptType) -> ElementType {
-    return {};
-  }
-}
-
-let s: SubscriptType = {};
-let c: C = {};
-let x: ElementType = c[s];
-
-// --- overloaded_builtin.carbon
-
-library "[[@TEST_NAME]]";
-
-impl (i32, i32) as Core.IndexWith(i32, i32) {
-  fn At[self: Self](subscript: i32) -> i32 {
-    return self.0;
-  }
-}
-
-let s: (i32, i32) = (1, 5);
-let e: i32 = s[0];
-
-// --- fail_invalid_subscript_type.carbon
-
-library "[[@TEST_NAME]]";
-
-class C { }
-class ElementType {}
-class SubscriptType {}
-
-impl C as Core.IndexWith(SubscriptType, ElementType) {
-  fn At[self: Self](subscript: SubscriptType) -> ElementType {
-    return {};
-  }
-}
-
-let c: C = {};
-// CHECK:STDERR: fail_invalid_subscript_type.carbon:[[@LINE+7]]:22: error: cannot implicitly convert expression of type `Core.IntLiteral` to `SubscriptType` [ConversionFailure]
-// CHECK:STDERR: let x: ElementType = c[0];
-// CHECK:STDERR:                      ^~~~
-// CHECK:STDERR: fail_invalid_subscript_type.carbon:[[@LINE+4]]:22: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(SubscriptType)` [MissingImplInMemberAccessNote]
-// CHECK:STDERR: let x: ElementType = c[0];
-// CHECK:STDERR:                      ^~~~
+// CHECK:STDERR: fail_wrong_index_with.carbon:[[@LINE+4]]:10: error: type `Core.IntLiteral` does not support indexing [TypeNotIndexable]
+// CHECK:STDERR: fn F() { 0[1]; }
+// CHECK:STDERR:          ^~~~
 // CHECK:STDERR:
-let x: ElementType = c[0];
+fn F() { 0[1]; }
 
-// --- fail_index_with_not_implemented.carbon
+// --- fail_missing_index_with.carbon
 
 library "[[@TEST_NAME]]";
 
-class C { }
-
-let c: C = {};
-// CHECK:STDERR: fail_index_with_not_implemented.carbon:[[@LINE+4]]:14: error: type `C` does not support indexing [TypeNotIndexable]
-// CHECK:STDERR: let x: i32 = c[0];
-// CHECK:STDERR:              ^~~~
+// CHECK:STDERR: fail_missing_index_with.carbon:[[@LINE+8]]:10: error: `Core.IndexWith` implicitly referenced here, but package `Core` not found [CoreNotFound]
+// CHECK:STDERR: fn F() { 0[1]; }
+// CHECK:STDERR:          ^~~~
 // CHECK:STDERR:
-let x: i32 = c[0];
+// CHECK:STDERR: fail_missing_index_with.carbon:[[@LINE+4]]:10: error: type `Core.IntLiteral` does not support indexing [TypeNotIndexable]
+// CHECK:STDERR: fn F() { 0[1]; }
+// CHECK:STDERR:          ^~~~
+// CHECK:STDERR:
+fn F() { 0[1]; }
 
+// --- core_wrong_arg_count.carbon
 
-// CHECK:STDOUT: --- overloaded_index.carbon
+package Core library "[[@TEST_NAME]]";
+
+interface IndexWith(SubscriptType:! type) {
+  fn At[self: Self](subscript: SubscriptType) -> ();
+}
+
+// --- wrong_arg_count.carbon
+
+library "[[@TEST_NAME]]";
+
+import Core library "core_wrong_arg_count";
+
+impl () as Core.IndexWith(()) {
+  fn At[self: Self](subscript: ()) -> () {
+    return ();
+  }
+}
+
+fn F() { ()[()]; }
+
+// CHECK:STDOUT: --- core_wrong_index_with.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %C: type = class_type @C [concrete]
+// CHECK:STDOUT:   %IndexWith: type = class_type @IndexWith [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .IndexWith = %IndexWith.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %IndexWith.decl: type = class_decl @IndexWith [concrete = constants.%IndexWith] {} {}
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @IndexWith {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%IndexWith
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_wrong_index_with.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %F.type: type = fn_type @F [concrete]
+// CHECK:STDOUT:   %F: %F.type = struct_value () [concrete]
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
+// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete]
+// CHECK:STDOUT:   %IndexWith: type = class_type @IndexWith [concrete]
 // CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
 // CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
-// CHECK:STDOUT:   %ElementType.e6b: type = class_type @ElementType [concrete]
-// CHECK:STDOUT:   %SubscriptType.8ee: type = class_type @SubscriptType [concrete]
-// CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
-// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.type.e80: type = facet_type <@IndexWith, @IndexWith(%SubscriptType.8ee, %ElementType.e6b)> [concrete]
-// CHECK:STDOUT:   %At.type.b3f: type = fn_type @At.1, @IndexWith(%SubscriptType.8ee, %ElementType.e6b) [concrete]
-// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness file.%IndexWith.impl_witness_table [concrete]
-// CHECK:STDOUT:   %pattern_type.c48: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %pattern_type.df7: type = pattern_type %SubscriptType.8ee [concrete]
-// CHECK:STDOUT:   %pattern_type.c39: type = pattern_type %ElementType.e6b [concrete]
-// CHECK:STDOUT:   %At.type.178: type = fn_type @At.2 [concrete]
-// CHECK:STDOUT:   %At.d43: %At.type.178 = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.facet: %IndexWith.type.e80 = facet_value %C, (%IndexWith.impl_witness) [concrete]
-// CHECK:STDOUT:   %ElementType.val: %ElementType.e6b = struct_value () [concrete]
-// CHECK:STDOUT:   %SubscriptType.val: %SubscriptType.8ee = struct_value () [concrete]
-// CHECK:STDOUT:   %C.val: %C = struct_value () [concrete]
-// CHECK:STDOUT:   %.d94: type = fn_type_with_self_type %At.type.b3f, %IndexWith.facet [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
 // CHECK:STDOUT:     .IndexWith = %Core.IndexWith
-// CHECK:STDOUT:     import Core//prelude
-// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:     import Core//core_wrong_index_with
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//prelude/operators/index, IndexWith, loaded [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT:   %Core.IndexWith: type = import_ref Core//core_wrong_index_with, IndexWith, loaded [concrete = constants.%IndexWith]
+// CHECK:STDOUT:   %Core.import_ref.8f2: <witness> = import_ref Core//core_wrong_index_with, loc4_18, loaded [concrete = constants.%complete_type]
+// CHECK:STDOUT:   %Core.import_ref.4c7 = import_ref Core//core_wrong_index_with, inst16 [no loc], unloaded
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
 // CHECK:STDOUT:     .Core = imports.%Core
-// CHECK:STDOUT:     .C = %C.decl
-// CHECK:STDOUT:     .ElementType = %ElementType.decl
-// CHECK:STDOUT:     .SubscriptType = %SubscriptType.decl
-// CHECK:STDOUT:     .s = %s
-// CHECK:STDOUT:     .c = %c
-// CHECK:STDOUT:     .x = %x
+// CHECK:STDOUT:     .F = %F.decl
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Core.import = import Core
-// CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %ElementType.decl: type = class_decl @ElementType [concrete = constants.%ElementType.e6b] {} {}
-// CHECK:STDOUT:   %SubscriptType.decl: type = class_decl @SubscriptType [concrete = constants.%SubscriptType.8ee] {} {}
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %C.ref: type = name_ref C, file.%C.decl [concrete = constants.%C]
-// CHECK:STDOUT:     %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
-// CHECK:STDOUT:     %IndexWith.ref: %IndexWith.type.504 = name_ref IndexWith, imports.%Core.IndexWith [concrete = constants.%IndexWith.generic]
-// CHECK:STDOUT:     %SubscriptType.ref: type = name_ref SubscriptType, file.%SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
-// CHECK:STDOUT:     %ElementType.ref: type = name_ref ElementType, file.%ElementType.decl [concrete = constants.%ElementType.e6b]
-// CHECK:STDOUT:     %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(constants.%SubscriptType.8ee, constants.%ElementType.e6b)> [concrete = constants.%IndexWith.type.e80]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %IndexWith.impl_witness_table = impl_witness_table (@impl.%At.decl), @impl [concrete]
-// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness %IndexWith.impl_witness_table [concrete = constants.%IndexWith.impl_witness]
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %s.patt: %pattern_type.df7 = binding_pattern s [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %SubscriptType.ref: type = name_ref SubscriptType, %SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
-// CHECK:STDOUT:   %.loc14_25.1: ref %SubscriptType.8ee = temporary_storage
-// CHECK:STDOUT:   %.loc14_25.2: init %SubscriptType.8ee = class_init (), %.loc14_25.1 [concrete = constants.%SubscriptType.val]
-// CHECK:STDOUT:   %.loc14_25.3: ref %SubscriptType.8ee = temporary %.loc14_25.1, %.loc14_25.2
-// CHECK:STDOUT:   %.loc14_25.4: ref %SubscriptType.8ee = converted @__global_init.%.loc14, %.loc14_25.3
-// CHECK:STDOUT:   %s: ref %SubscriptType.8ee = bind_name s, %.loc14_25.4
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %c.patt: %pattern_type.c48 = binding_pattern c [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %C.ref: type = name_ref C, %C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %.loc15_13.1: ref %C = temporary_storage
-// CHECK:STDOUT:   %.loc15_13.2: init %C = class_init (), %.loc15_13.1 [concrete = constants.%C.val]
-// CHECK:STDOUT:   %.loc15_13.3: ref %C = temporary %.loc15_13.1, %.loc15_13.2
-// CHECK:STDOUT:   %.loc15_13.4: ref %C = converted @__global_init.%.loc15, %.loc15_13.3
-// CHECK:STDOUT:   %c: ref %C = bind_name c, %.loc15_13.4
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %x.patt: %pattern_type.c39 = binding_pattern x [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %ElementType.ref: type = name_ref ElementType, %ElementType.decl [concrete = constants.%ElementType.e6b]
-// CHECK:STDOUT:   %.loc16: ref %ElementType.e6b = temporary @__global_init.%.loc16_25, @__global_init.%At.call
-// CHECK:STDOUT:   %x: ref %ElementType.e6b = bind_name x, %.loc16
+// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [concrete = constants.%F] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %C.ref as %IndexWith.type {
-// CHECK:STDOUT:   %At.decl: %At.type.178 = fn_decl @At.2 [concrete = constants.%At.d43] {
-// CHECK:STDOUT:     %self.patt: %pattern_type.c48 = binding_pattern self [concrete]
-// CHECK:STDOUT:     %self.param_patt: %pattern_type.c48 = value_param_pattern %self.patt, call_param0 [concrete]
-// CHECK:STDOUT:     %subscript.patt: %pattern_type.df7 = binding_pattern subscript [concrete]
-// CHECK:STDOUT:     %subscript.param_patt: %pattern_type.df7 = value_param_pattern %subscript.patt, call_param1 [concrete]
-// CHECK:STDOUT:     %return.patt: %pattern_type.c39 = return_slot_pattern [concrete]
-// CHECK:STDOUT:     %return.param_patt: %pattern_type.c39 = out_param_pattern %return.patt, call_param2 [concrete]
-// CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %ElementType.ref: type = name_ref ElementType, file.%ElementType.decl [concrete = constants.%ElementType.e6b]
-// CHECK:STDOUT:     %self.param: %C = value_param call_param0
-// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.%C.ref [concrete = constants.%C]
-// CHECK:STDOUT:     %self: %C = bind_name self, %self.param
-// CHECK:STDOUT:     %subscript.param: %SubscriptType.8ee = value_param call_param1
-// CHECK:STDOUT:     %SubscriptType.ref: type = name_ref SubscriptType, file.%SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
-// CHECK:STDOUT:     %subscript: %SubscriptType.8ee = bind_name subscript, %subscript.param
-// CHECK:STDOUT:     %return.param: ref %ElementType.e6b = out_param call_param2
-// CHECK:STDOUT:     %return: ref %ElementType.e6b = return_slot %return.param
-// CHECK:STDOUT:   }
+// CHECK:STDOUT: class @IndexWith [from "core_wrong_index_with.carbon"] {
+// CHECK:STDOUT:   complete_type_witness = imports.%Core.import_ref.8f2
 // CHECK:STDOUT:
 // CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .SubscriptType = <poisoned>
-// CHECK:STDOUT:   .ElementType = <poisoned>
-// CHECK:STDOUT:   .At = %At.decl
-// CHECK:STDOUT:   witness = file.%IndexWith.impl_witness
+// CHECK:STDOUT:   .Self = imports.%Core.import_ref.4c7
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: class @C {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%C
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: class @ElementType {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%ElementType.e6b
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: class @SubscriptType {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%SubscriptType.8ee
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @At.2(%self.param: %C, %subscript.param: %SubscriptType.8ee) -> %return.param: %ElementType.e6b {
+// CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc10_13.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc10_13.2: init %ElementType.e6b = class_init (), %return [concrete = constants.%ElementType.val]
-// CHECK:STDOUT:   %.loc10_14: init %ElementType.e6b = converted %.loc10_13.1, %.loc10_13.2 [concrete = constants.%ElementType.val]
-// CHECK:STDOUT:   return %.loc10_14 to %return
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @__global_init() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc14: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc15: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %c.ref: ref %C = name_ref c, file.%c
-// CHECK:STDOUT:   %s.ref: ref %SubscriptType.8ee = name_ref s, file.%s
-// CHECK:STDOUT:   %.loc16_24: %SubscriptType.8ee = bind_value %s.ref
-// CHECK:STDOUT:   %impl.elem0: %.d94 = impl_witness_access constants.%IndexWith.impl_witness, element0 [concrete = constants.%At.d43]
-// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %c.ref, %impl.elem0
-// CHECK:STDOUT:   %.loc16_25: ref %ElementType.e6b = temporary_storage
-// CHECK:STDOUT:   %.loc16_22: %C = bind_value %c.ref
-// CHECK:STDOUT:   %At.call: init %ElementType.e6b = call %bound_method(%.loc16_22, %.loc16_24) to %.loc16_25
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
+// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1]
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- overloaded_builtin.carbon
+// CHECK:STDOUT: --- fail_missing_index_with.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
-// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
-// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
-// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
-// CHECK:STDOUT:   %tuple.type.24b: type = tuple_type (type, type) [concrete]
-// CHECK:STDOUT:   %tuple.type.d07: type = tuple_type (%i32, %i32) [concrete]
-// CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
-// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.type.917: type = facet_type <@IndexWith, @IndexWith(%i32, %i32)> [concrete]
-// CHECK:STDOUT:   %At.type.d77: type = fn_type @At.1, @IndexWith(%i32, %i32) [concrete]
-// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness file.%IndexWith.impl_witness_table [concrete]
-// CHECK:STDOUT:   %pattern_type.511: type = pattern_type %tuple.type.d07 [concrete]
-// CHECK:STDOUT:   %pattern_type.7ce: type = pattern_type %i32 [concrete]
-// CHECK:STDOUT:   %At.type.9ac: type = fn_type @At.2 [concrete]
-// CHECK:STDOUT:   %At.642: %At.type.9ac = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.facet: %IndexWith.type.917 = facet_value %tuple.type.d07, (%IndexWith.impl_witness) [concrete]
-// CHECK:STDOUT:   %int_0.5c6: Core.IntLiteral = int_value 0 [concrete]
-// CHECK:STDOUT:   %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
-// CHECK:STDOUT:   %int_5.64b: Core.IntLiteral = int_value 5 [concrete]
-// CHECK:STDOUT:   %tuple.type.f94: type = tuple_type (Core.IntLiteral, Core.IntLiteral) [concrete]
-// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
-// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
-// CHECK:STDOUT:   %ImplicitAs.type.205: type = facet_type <@ImplicitAs, @ImplicitAs(%i32)> [concrete]
-// CHECK:STDOUT:   %Convert.type.1b6: type = fn_type @Convert.1, @ImplicitAs(%i32) [concrete]
-// CHECK:STDOUT:   %To.c80: Core.IntLiteral = bind_symbolic_name To, 0 [symbolic]
-// CHECK:STDOUT:   %Convert.type.0f9: type = fn_type @Convert.2, @impl.4f9(%To.c80) [symbolic]
-// CHECK:STDOUT:   %Convert.f06: %Convert.type.0f9 = struct_value () [symbolic]
-// CHECK:STDOUT:   %ImplicitAs.impl_witness.c75: <witness> = impl_witness imports.%ImplicitAs.impl_witness_table.a2f, @impl.4f9(%int_32) [concrete]
-// CHECK:STDOUT:   %Convert.type.035: type = fn_type @Convert.2, @impl.4f9(%int_32) [concrete]
-// CHECK:STDOUT:   %Convert.956: %Convert.type.035 = struct_value () [concrete]
-// CHECK:STDOUT:   %ImplicitAs.facet: %ImplicitAs.type.205 = facet_value Core.IntLiteral, (%ImplicitAs.impl_witness.c75) [concrete]
-// CHECK:STDOUT:   %.9c3: type = fn_type_with_self_type %Convert.type.1b6, %ImplicitAs.facet [concrete]
-// CHECK:STDOUT:   %Convert.bound.ab5: <bound method> = bound_method %int_1.5b8, %Convert.956 [concrete]
-// CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.956, @Convert.2(%int_32) [concrete]
-// CHECK:STDOUT:   %bound_method.9a1: <bound method> = bound_method %int_1.5b8, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_1.5d2: %i32 = int_value 1 [concrete]
-// CHECK:STDOUT:   %Convert.bound.4e6: <bound method> = bound_method %int_5.64b, %Convert.956 [concrete]
-// CHECK:STDOUT:   %bound_method.a25: <bound method> = bound_method %int_5.64b, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_5.0f6: %i32 = int_value 5 [concrete]
-// CHECK:STDOUT:   %tuple: %tuple.type.d07 = tuple_value (%int_1.5d2, %int_5.0f6) [concrete]
-// CHECK:STDOUT:   %Convert.bound.d04: <bound method> = bound_method %int_0.5c6, %Convert.956 [concrete]
-// CHECK:STDOUT:   %bound_method.b6e: <bound method> = bound_method %int_0.5c6, %Convert.specific_fn [concrete]
-// CHECK:STDOUT:   %int_0.6a9: %i32 = int_value 0 [concrete]
-// CHECK:STDOUT:   %.2dc: type = fn_type_with_self_type %At.type.d77, %IndexWith.facet [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
-// CHECK:STDOUT:     .Int = %Core.Int
-// CHECK:STDOUT:     .IndexWith = %Core.IndexWith
-// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
-// CHECK:STDOUT:     import Core//prelude
-// CHECK:STDOUT:     import Core//prelude/...
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/types/int, Int, loaded [concrete = constants.%Int.generic]
-// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//prelude/operators/index, IndexWith, loaded [concrete = constants.%IndexWith.generic]
-// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/operators/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
-// CHECK:STDOUT:   %Core.import_ref.a5b: @impl.4f9.%Convert.type (%Convert.type.0f9) = import_ref Core//prelude/types/int, loc19_39, loaded [symbolic = @impl.4f9.%Convert (constants.%Convert.f06)]
-// CHECK:STDOUT:   %ImplicitAs.impl_witness_table.a2f = impl_witness_table (%Core.import_ref.a5b), @impl.4f9 [concrete]
+// CHECK:STDOUT:   %F.type: type = fn_type @F [concrete]
+// CHECK:STDOUT:   %F: %F.type = struct_value () [concrete]
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
+// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .Core = imports.%Core
-// CHECK:STDOUT:     .s = %s
-// CHECK:STDOUT:     .e = %e
+// CHECK:STDOUT:     .F = %F.decl
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.import = import Core
-// CHECK:STDOUT:   impl_decl @impl.18b [concrete] {} {
-// CHECK:STDOUT:     %int_32.loc4_7: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc4_7: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:     %int_32.loc4_12: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc4_12: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:     %.loc4_15.1: %tuple.type.24b = tuple_literal (%i32.loc4_7, %i32.loc4_12)
-// CHECK:STDOUT:     %.loc4_15.2: type = converted %.loc4_15.1, constants.%tuple.type.d07 [concrete = constants.%tuple.type.d07]
-// CHECK:STDOUT:     %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
-// CHECK:STDOUT:     %IndexWith.ref: %IndexWith.type.504 = name_ref IndexWith, imports.%Core.IndexWith [concrete = constants.%IndexWith.generic]
-// CHECK:STDOUT:     %int_32.loc4_35: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc4_35: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:     %int_32.loc4_40: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc4_40: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:     %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(constants.%i32, constants.%i32)> [concrete = constants.%IndexWith.type.917]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %IndexWith.impl_witness_table = impl_witness_table (@impl.18b.%At.decl), @impl.18b [concrete]
-// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness %IndexWith.impl_witness_table [concrete = constants.%IndexWith.impl_witness]
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %s.patt: %pattern_type.511 = binding_pattern s [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.loc10_17.1: type = splice_block %.loc10_17.3 [concrete = constants.%tuple.type.d07] {
-// CHECK:STDOUT:     %int_32.loc10_9: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc10_9: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:     %int_32.loc10_14: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc10_14: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:     %.loc10_17.2: %tuple.type.24b = tuple_literal (%i32.loc10_9, %i32.loc10_14)
-// CHECK:STDOUT:     %.loc10_17.3: type = converted %.loc10_17.2, constants.%tuple.type.d07 [concrete = constants.%tuple.type.d07]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %impl.elem0.loc10_26.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:   %bound_method.loc10_26.1: <bound method> = bound_method @__global_init.%int_1, %impl.elem0.loc10_26.1 [concrete = constants.%Convert.bound.ab5]
-// CHECK:STDOUT:   %specific_fn.loc10_26.1: <specific function> = specific_function %impl.elem0.loc10_26.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:   %bound_method.loc10_26.2: <bound method> = bound_method @__global_init.%int_1, %specific_fn.loc10_26.1 [concrete = constants.%bound_method.9a1]
-// CHECK:STDOUT:   %int.convert_checked.loc10_26.1: init %i32 = call %bound_method.loc10_26.2(@__global_init.%int_1) [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc10_26.1: %i32 = value_of_initializer %int.convert_checked.loc10_26.1 [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:   %.loc10_26.2: %i32 = converted @__global_init.%int_1, %.loc10_26.1 [concrete = constants.%int_1.5d2]
-// CHECK:STDOUT:   %impl.elem0.loc10_26.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:   %bound_method.loc10_26.3: <bound method> = bound_method @__global_init.%int_5, %impl.elem0.loc10_26.2 [concrete = constants.%Convert.bound.4e6]
-// CHECK:STDOUT:   %specific_fn.loc10_26.2: <specific function> = specific_function %impl.elem0.loc10_26.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:   %bound_method.loc10_26.4: <bound method> = bound_method @__global_init.%int_5, %specific_fn.loc10_26.2 [concrete = constants.%bound_method.a25]
-// CHECK:STDOUT:   %int.convert_checked.loc10_26.2: init %i32 = call %bound_method.loc10_26.4(@__global_init.%int_5) [concrete = constants.%int_5.0f6]
-// CHECK:STDOUT:   %.loc10_26.3: %i32 = value_of_initializer %int.convert_checked.loc10_26.2 [concrete = constants.%int_5.0f6]
-// CHECK:STDOUT:   %.loc10_26.4: %i32 = converted @__global_init.%int_5, %.loc10_26.3 [concrete = constants.%int_5.0f6]
-// CHECK:STDOUT:   %tuple: %tuple.type.d07 = tuple_value (%.loc10_26.2, %.loc10_26.4) [concrete = constants.%tuple]
-// CHECK:STDOUT:   %.loc10_26.5: %tuple.type.d07 = converted @__global_init.%.loc10, %tuple [concrete = constants.%tuple]
-// CHECK:STDOUT:   %s: %tuple.type.d07 = bind_name s, %.loc10_26.5
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %e.patt: %pattern_type.7ce = binding_pattern e [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.loc11_8: type = splice_block %i32.loc11 [concrete = constants.%i32] {
-// CHECK:STDOUT:     %int_32.loc11: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc11: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.loc11_17.1: ref %i32 = temporary_storage
-// CHECK:STDOUT:   %.loc11_17.2: ref %i32 = temporary %.loc11_17.1, @__global_init.%At.call
-// CHECK:STDOUT:   %e: ref %i32 = bind_name e, %.loc11_17.2
+// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [concrete = constants.%F] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl.18b: %.loc4_15.2 as %IndexWith.type {
-// CHECK:STDOUT:   %At.decl: %At.type.9ac = fn_decl @At.2 [concrete = constants.%At.642] {
-// CHECK:STDOUT:     %self.patt: %pattern_type.511 = binding_pattern self [concrete]
-// CHECK:STDOUT:     %self.param_patt: %pattern_type.511 = value_param_pattern %self.patt, call_param0 [concrete]
-// CHECK:STDOUT:     %subscript.patt: %pattern_type.7ce = binding_pattern subscript [concrete]
-// CHECK:STDOUT:     %subscript.param_patt: %pattern_type.7ce = value_param_pattern %subscript.patt, call_param1 [concrete]
-// CHECK:STDOUT:     %return.patt: %pattern_type.7ce = return_slot_pattern [concrete]
-// CHECK:STDOUT:     %return.param_patt: %pattern_type.7ce = out_param_pattern %return.patt, call_param2 [concrete]
+// CHECK:STDOUT: fn @F() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
+// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1]
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- core_wrong_arg_count.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic]
+// CHECK:STDOUT:   %pattern_type.98f: type = pattern_type type [concrete]
+// CHECK:STDOUT:   %IndexWith.type.68b: type = generic_interface_type @IndexWith [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
+// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.68b = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.type.b94: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic]
+// CHECK:STDOUT:   %Self: %IndexWith.type.b94 = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %Self.as_type: type = facet_access_type %Self [symbolic]
+// CHECK:STDOUT:   %pattern_type.2ad: type = pattern_type %Self.as_type [symbolic]
+// CHECK:STDOUT:   %pattern_type.7dc: type = pattern_type %SubscriptType [symbolic]
+// CHECK:STDOUT:   %pattern_type.cb1: type = pattern_type %empty_tuple.type [concrete]
+// CHECK:STDOUT:   %At.type: type = fn_type @At, @IndexWith(%SubscriptType) [symbolic]
+// CHECK:STDOUT:   %At: %At.type = struct_value () [symbolic]
+// CHECK:STDOUT:   %IndexWith.assoc_type: type = assoc_entity_type @IndexWith, @IndexWith(%SubscriptType) [symbolic]
+// CHECK:STDOUT:   %assoc0: %IndexWith.assoc_type = assoc_entity element0, @IndexWith.%At.decl [symbolic]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .IndexWith = %IndexWith.decl
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %IndexWith.decl: %IndexWith.type.68b = interface_decl @IndexWith [concrete = constants.%IndexWith.generic] {
+// CHECK:STDOUT:     %SubscriptType.patt: %pattern_type.98f = symbolic_binding_pattern SubscriptType, 0 [concrete]
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %int_32.loc5_40: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32.loc5_40: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:     %self.param: %tuple.type.d07 = value_param call_param0
-// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.18b.%.loc4_15.2 [concrete = constants.%tuple.type.d07]
-// CHECK:STDOUT:     %self: %tuple.type.d07 = bind_name self, %self.param
-// CHECK:STDOUT:     %subscript.param: %i32 = value_param call_param1
-// CHECK:STDOUT:     %.loc5: type = splice_block %i32.loc5_32 [concrete = constants.%i32] {
-// CHECK:STDOUT:       %int_32.loc5_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:       %i32.loc5_32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %SubscriptType.loc4_21.1: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType.loc4_21.2 (constants.%SubscriptType)]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: generic interface @IndexWith(%SubscriptType.loc4_21.1: type) {
+// CHECK:STDOUT:   %SubscriptType.loc4_21.2: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType.loc4_21.2 (constants.%SubscriptType)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(%SubscriptType.loc4_21.2)> [symbolic = %IndexWith.type (constants.%IndexWith.type.b94)]
+// CHECK:STDOUT:   %Self.2: @IndexWith.%IndexWith.type (%IndexWith.type.b94) = bind_symbolic_name Self, 1 [symbolic = %Self.2 (constants.%Self)]
+// CHECK:STDOUT:   %At.type: type = fn_type @At, @IndexWith(%SubscriptType.loc4_21.2) [symbolic = %At.type (constants.%At.type)]
+// CHECK:STDOUT:   %At: @IndexWith.%At.type (%At.type) = struct_value () [symbolic = %At (constants.%At)]
+// CHECK:STDOUT:   %IndexWith.assoc_type: type = assoc_entity_type @IndexWith, @IndexWith(%SubscriptType.loc4_21.2) [symbolic = %IndexWith.assoc_type (constants.%IndexWith.assoc_type)]
+// CHECK:STDOUT:   %assoc0.loc5_52.2: @IndexWith.%IndexWith.assoc_type (%IndexWith.assoc_type) = assoc_entity element0, %At.decl [symbolic = %assoc0.loc5_52.2 (constants.%assoc0)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   interface {
+// CHECK:STDOUT:     %Self.1: @IndexWith.%IndexWith.type (%IndexWith.type.b94) = bind_symbolic_name Self, 1 [symbolic = %Self.2 (constants.%Self)]
+// CHECK:STDOUT:     %At.decl: @IndexWith.%At.type (%At.type) = fn_decl @At [symbolic = @IndexWith.%At (constants.%At)] {
+// CHECK:STDOUT:       %self.patt: @At.%pattern_type.loc5_9 (%pattern_type.2ad) = binding_pattern self [concrete]
+// CHECK:STDOUT:       %self.param_patt: @At.%pattern_type.loc5_9 (%pattern_type.2ad) = value_param_pattern %self.patt, call_param0 [concrete]
+// CHECK:STDOUT:       %subscript.patt: @At.%pattern_type.loc5_21 (%pattern_type.7dc) = binding_pattern subscript [concrete]
+// CHECK:STDOUT:       %subscript.param_patt: @At.%pattern_type.loc5_21 (%pattern_type.7dc) = value_param_pattern %subscript.patt, call_param1 [concrete]
+// CHECK:STDOUT:       %return.patt: %pattern_type.cb1 = return_slot_pattern [concrete]
+// CHECK:STDOUT:       %return.param_patt: %pattern_type.cb1 = out_param_pattern %return.patt, call_param2 [concrete]
+// CHECK:STDOUT:     } {
+// CHECK:STDOUT:       %.loc5_51.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:       %.loc5_51.2: type = converted %.loc5_51.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:       %self.param: @At.%Self.as_type.loc5_15.1 (%Self.as_type) = value_param call_param0
+// CHECK:STDOUT:       %.loc5_15.1: type = splice_block %.loc5_15.3 [symbolic = %Self.as_type.loc5_15.1 (constants.%Self.as_type)] {
+// CHECK:STDOUT:         %.loc5_15.2: @At.%IndexWith.type (%IndexWith.type.b94) = specific_constant @IndexWith.%Self.1, @IndexWith(constants.%SubscriptType) [symbolic = %Self (constants.%Self)]
+// CHECK:STDOUT:         %Self.ref: @At.%IndexWith.type (%IndexWith.type.b94) = name_ref Self, %.loc5_15.2 [symbolic = %Self (constants.%Self)]
+// CHECK:STDOUT:         %Self.as_type.loc5_15.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc5_15.1 (constants.%Self.as_type)]
+// CHECK:STDOUT:         %.loc5_15.3: type = converted %Self.ref, %Self.as_type.loc5_15.2 [symbolic = %Self.as_type.loc5_15.1 (constants.%Self.as_type)]
+// CHECK:STDOUT:       }
+// CHECK:STDOUT:       %self: @At.%Self.as_type.loc5_15.1 (%Self.as_type) = bind_name self, %self.param
+// CHECK:STDOUT:       %subscript.param: @At.%SubscriptType (%SubscriptType) = value_param call_param1
+// CHECK:STDOUT:       %SubscriptType.ref: type = name_ref SubscriptType, @IndexWith.%SubscriptType.loc4_21.1 [symbolic = %SubscriptType (constants.%SubscriptType)]
+// CHECK:STDOUT:       %subscript: @At.%SubscriptType (%SubscriptType) = bind_name subscript, %subscript.param
+// CHECK:STDOUT:       %return.param: ref %empty_tuple.type = out_param call_param2
+// CHECK:STDOUT:       %return: ref %empty_tuple.type = return_slot %return.param
 // CHECK:STDOUT:     }
-// CHECK:STDOUT:     %subscript: %i32 = bind_name subscript, %subscript.param
-// CHECK:STDOUT:     %return.param: ref %i32 = out_param call_param2
-// CHECK:STDOUT:     %return: ref %i32 = return_slot %return.param
+// CHECK:STDOUT:     %assoc0.loc5_52.1: @IndexWith.%IndexWith.assoc_type (%IndexWith.assoc_type) = assoc_entity element0, %At.decl [symbolic = %assoc0.loc5_52.2 (constants.%assoc0)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = %Self.1
+// CHECK:STDOUT:     .SubscriptType = <poisoned>
+// CHECK:STDOUT:     .At = %assoc0.loc5_52.1
+// CHECK:STDOUT:     witness = (%At.decl)
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .At = %At.decl
-// CHECK:STDOUT:   witness = file.%IndexWith.impl_witness
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @At.2(%self.param: %tuple.type.d07, %subscript.param: %i32) -> %i32 {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %self.ref: %tuple.type.d07 = name_ref self, %self
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0.5c6]
-// CHECK:STDOUT:   %tuple.elem0: %i32 = tuple_access %self.ref, element0
-// CHECK:STDOUT:   return %tuple.elem0
+// CHECK:STDOUT: generic fn @At(@IndexWith.%SubscriptType.loc4_21.1: type, @IndexWith.%Self.1: @IndexWith.%IndexWith.type (%IndexWith.type.b94)) {
+// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType (constants.%SubscriptType)]
+// CHECK:STDOUT:   %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic = %IndexWith.type (constants.%IndexWith.type.b94)]
+// CHECK:STDOUT:   %Self: @At.%IndexWith.type (%IndexWith.type.b94) = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self)]
+// CHECK:STDOUT:   %Self.as_type.loc5_15.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc5_15.1 (constants.%Self.as_type)]
+// CHECK:STDOUT:   %pattern_type.loc5_9: type = pattern_type %Self.as_type.loc5_15.1 [symbolic = %pattern_type.loc5_9 (constants.%pattern_type.2ad)]
+// CHECK:STDOUT:   %pattern_type.loc5_21: type = pattern_type %SubscriptType [symbolic = %pattern_type.loc5_21 (constants.%pattern_type.7dc)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   fn(%self.param: @At.%Self.as_type.loc5_15.1 (%Self.as_type), %subscript.param: @At.%SubscriptType (%SubscriptType)) -> %empty_tuple.type;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @__global_init() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
-// CHECK:STDOUT:   %int_5: Core.IntLiteral = int_value 5 [concrete = constants.%int_5.64b]
-// CHECK:STDOUT:   %.loc10: %tuple.type.f94 = tuple_literal (%int_1, %int_5)
-// CHECK:STDOUT:   %s.ref: %tuple.type.d07 = name_ref s, file.%s
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0.5c6]
-// CHECK:STDOUT:   %impl.elem0.loc11_17.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
-// CHECK:STDOUT:   %bound_method.loc11_17.1: <bound method> = bound_method %int_0, %impl.elem0.loc11_17.1 [concrete = constants.%Convert.bound.d04]
-// CHECK:STDOUT:   %specific_fn: <specific function> = specific_function %impl.elem0.loc11_17.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
-// CHECK:STDOUT:   %bound_method.loc11_17.2: <bound method> = bound_method %int_0, %specific_fn [concrete = constants.%bound_method.b6e]
-// CHECK:STDOUT:   %int.convert_checked: init %i32 = call %bound_method.loc11_17.2(%int_0) [concrete = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc11_17.1: %i32 = value_of_initializer %int.convert_checked [concrete = constants.%int_0.6a9]
-// CHECK:STDOUT:   %.loc11_17.2: %i32 = converted %int_0, %.loc11_17.1 [concrete = constants.%int_0.6a9]
-// CHECK:STDOUT:   %impl.elem0.loc11_17.2: %.2dc = impl_witness_access constants.%IndexWith.impl_witness, element0 [concrete = constants.%At.642]
-// CHECK:STDOUT:   %bound_method.loc11_17.3: <bound method> = bound_method %s.ref, %impl.elem0.loc11_17.2
-// CHECK:STDOUT:   %At.call: init %i32 = call %bound_method.loc11_17.3(%s.ref, %.loc11_17.2)
-// CHECK:STDOUT:   return
+// CHECK:STDOUT: specific @IndexWith(constants.%SubscriptType) {
+// CHECK:STDOUT:   %SubscriptType.loc4_21.2 => constants.%SubscriptType
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_invalid_subscript_type.carbon
+// CHECK:STDOUT: specific @At(constants.%SubscriptType, constants.%Self) {
+// CHECK:STDOUT:   %SubscriptType => constants.%SubscriptType
+// CHECK:STDOUT:   %IndexWith.type => constants.%IndexWith.type.b94
+// CHECK:STDOUT:   %Self => constants.%Self
+// CHECK:STDOUT:   %Self.as_type.loc5_15.1 => constants.%Self.as_type
+// CHECK:STDOUT:   %pattern_type.loc5_9 => constants.%pattern_type.2ad
+// CHECK:STDOUT:   %pattern_type.loc5_21 => constants.%pattern_type.7dc
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- wrong_arg_count.carbon
 // CHECK:STDOUT:
 // CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %C: type = class_type @C [concrete]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
-// CHECK:STDOUT:   %ElementType.e6b: type = class_type @ElementType [concrete]
-// CHECK:STDOUT:   %SubscriptType.8ee: type = class_type @SubscriptType [concrete]
+// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
 // CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
 // CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.type.e80: type = facet_type <@IndexWith, @IndexWith(%SubscriptType.8ee, %ElementType.e6b)> [concrete]
-// CHECK:STDOUT:   %At.type.b3f: type = fn_type @At.1, @IndexWith(%SubscriptType.8ee, %ElementType.e6b) [concrete]
+// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic]
+// CHECK:STDOUT:   %IndexWith.type.bd2: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic]
+// CHECK:STDOUT:   %Self.30a: %IndexWith.type.bd2 = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %At.type.cf4: type = fn_type @At.1, @IndexWith(%SubscriptType) [symbolic]
+// CHECK:STDOUT:   %At.281: %At.type.cf4 = struct_value () [symbolic]
+// CHECK:STDOUT:   %pattern_type.cb1: type = pattern_type %empty_tuple.type [concrete]
+// CHECK:STDOUT:   %Self.as_type: type = facet_access_type %Self.30a [symbolic]
+// CHECK:STDOUT:   %pattern_type.e1a: type = pattern_type %Self.as_type [symbolic]
+// CHECK:STDOUT:   %pattern_type.7dc: type = pattern_type %SubscriptType [symbolic]
+// CHECK:STDOUT:   %IndexWith.assoc_type.290: type = assoc_entity_type @IndexWith, @IndexWith(%SubscriptType) [symbolic]
+// CHECK:STDOUT:   %assoc0.af8: %IndexWith.assoc_type.290 = assoc_entity element0, imports.%Core.import_ref.e99 [symbolic]
+// CHECK:STDOUT:   %IndexWith.type.a51: type = facet_type <@IndexWith, @IndexWith(%empty_tuple.type)> [concrete]
+// CHECK:STDOUT:   %Self.8f0: %IndexWith.type.a51 = bind_symbolic_name Self, 1 [symbolic]
+// CHECK:STDOUT:   %At.type.969: type = fn_type @At.1, @IndexWith(%empty_tuple.type) [concrete]
+// CHECK:STDOUT:   %At.9b9: %At.type.969 = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.assoc_type.3d4: type = assoc_entity_type @IndexWith, @IndexWith(%empty_tuple.type) [concrete]
+// CHECK:STDOUT:   %assoc0.21b: %IndexWith.assoc_type.3d4 = assoc_entity element0, imports.%Core.import_ref.e99 [concrete]
 // CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness file.%IndexWith.impl_witness_table [concrete]
-// CHECK:STDOUT:   %pattern_type.c48: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %pattern_type.df7: type = pattern_type %SubscriptType.8ee [concrete]
-// CHECK:STDOUT:   %pattern_type.c39: type = pattern_type %ElementType.e6b [concrete]
-// CHECK:STDOUT:   %At.type.178: type = fn_type @At.2 [concrete]
-// CHECK:STDOUT:   %At.d43: %At.type.178 = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.facet: %IndexWith.type.e80 = facet_value %C, (%IndexWith.impl_witness) [concrete]
-// CHECK:STDOUT:   %ElementType.val: %ElementType.e6b = struct_value () [concrete]
-// CHECK:STDOUT:   %C.val: %C = struct_value () [concrete]
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
-// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
-// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
-// CHECK:STDOUT:   %.d94: type = fn_type_with_self_type %At.type.b3f, %IndexWith.facet [concrete]
+// CHECK:STDOUT:   %At.type.486: type = fn_type @At.2 [concrete]
+// CHECK:STDOUT:   %At.7c4: %At.type.486 = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.facet: %IndexWith.type.a51 = facet_value %empty_tuple.type, (%IndexWith.impl_witness) [concrete]
+// CHECK:STDOUT:   %empty_tuple: %empty_tuple.type = tuple_value () [concrete]
+// CHECK:STDOUT:   %F.type: type = fn_type @F [concrete]
+// CHECK:STDOUT:   %F: %F.type = struct_value () [concrete]
+// CHECK:STDOUT:   %assoc0.e1e: %IndexWith.assoc_type.290 = assoc_entity element0, imports.%Core.import_ref.981 [symbolic]
+// CHECK:STDOUT:   %.ffc: type = fn_type_with_self_type %At.type.969, %IndexWith.facet [concrete]
+// CHECK:STDOUT:   %At.bound: <bound method> = bound_method %empty_tuple, %At.7c4 [concrete]
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: imports {
 // CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
 // CHECK:STDOUT:     .IndexWith = %Core.IndexWith
-// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
-// CHECK:STDOUT:     import Core//prelude
-// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:     import Core//core_wrong_arg_count
 // CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//prelude/operators/index, IndexWith, loaded [concrete = constants.%IndexWith.generic]
-// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/operators/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
+// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//core_wrong_arg_count, IndexWith, loaded [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT:   %Core.import_ref.5ab3ec.1: type = import_ref Core//core_wrong_arg_count, loc4_21, loaded [symbolic = @IndexWith.%SubscriptType (constants.%SubscriptType)]
+// CHECK:STDOUT:   %Core.import_ref.68a = import_ref Core//core_wrong_arg_count, inst25 [no loc], unloaded
+// CHECK:STDOUT:   %Core.import_ref.613: @IndexWith.%IndexWith.assoc_type (%IndexWith.assoc_type.290) = import_ref Core//core_wrong_arg_count, loc5_52, loaded [symbolic = @IndexWith.%assoc0 (constants.%assoc0.e1e)]
+// CHECK:STDOUT:   %Core.At: @IndexWith.%At.type (%At.type.cf4) = import_ref Core//core_wrong_arg_count, At, loaded [symbolic = @IndexWith.%At (constants.%At.281)]
+// CHECK:STDOUT:   %Core.import_ref.5ab3ec.2: type = import_ref Core//core_wrong_arg_count, loc4_21, loaded [symbolic = @IndexWith.%SubscriptType (constants.%SubscriptType)]
+// CHECK:STDOUT:   %Core.import_ref.fb5: @IndexWith.%IndexWith.type (%IndexWith.type.bd2) = import_ref Core//core_wrong_arg_count, inst25 [no loc], loaded [symbolic = @IndexWith.%Self (constants.%Self.30a)]
+// CHECK:STDOUT:   %Core.import_ref.e99: @IndexWith.%At.type (%At.type.cf4) = import_ref Core//core_wrong_arg_count, loc5_52, loaded [symbolic = @IndexWith.%At (constants.%At.281)]
+// CHECK:STDOUT:   %Core.import_ref.981 = import_ref Core//core_wrong_arg_count, loc5_52, unloaded
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: file {
 // CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
 // CHECK:STDOUT:     .Core = imports.%Core
-// CHECK:STDOUT:     .C = %C.decl
-// CHECK:STDOUT:     .ElementType = %ElementType.decl
-// CHECK:STDOUT:     .SubscriptType = %SubscriptType.decl
-// CHECK:STDOUT:     .c = %c
-// CHECK:STDOUT:     .x = %x
+// CHECK:STDOUT:     .F = %F.decl
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %Core.import = import Core
-// CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   %ElementType.decl: type = class_decl @ElementType [concrete = constants.%ElementType.e6b] {} {}
-// CHECK:STDOUT:   %SubscriptType.decl: type = class_decl @SubscriptType [concrete = constants.%SubscriptType.8ee] {} {}
 // CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %C.ref: type = name_ref C, file.%C.decl [concrete = constants.%C]
+// CHECK:STDOUT:     %.loc6_7.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc6_7.2: type = converted %.loc6_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
 // CHECK:STDOUT:     %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
 // CHECK:STDOUT:     %IndexWith.ref: %IndexWith.type.504 = name_ref IndexWith, imports.%Core.IndexWith [concrete = constants.%IndexWith.generic]
-// CHECK:STDOUT:     %SubscriptType.ref: type = name_ref SubscriptType, file.%SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
-// CHECK:STDOUT:     %ElementType.ref: type = name_ref ElementType, file.%ElementType.decl [concrete = constants.%ElementType.e6b]
-// CHECK:STDOUT:     %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(constants.%SubscriptType.8ee, constants.%ElementType.e6b)> [concrete = constants.%IndexWith.type.e80]
+// CHECK:STDOUT:     %.loc6_28: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc6_29: type = converted %.loc6_28, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(constants.%empty_tuple.type)> [concrete = constants.%IndexWith.type.a51]
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:   %IndexWith.impl_witness_table = impl_witness_table (@impl.%At.decl), @impl [concrete]
 // CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness %IndexWith.impl_witness_table [concrete = constants.%IndexWith.impl_witness]
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %c.patt: %pattern_type.c48 = binding_pattern c [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %C.ref: type = name_ref C, %C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %.loc14_13.1: ref %C = temporary_storage
-// CHECK:STDOUT:   %.loc14_13.2: init %C = class_init (), %.loc14_13.1 [concrete = constants.%C.val]
-// CHECK:STDOUT:   %.loc14_13.3: ref %C = temporary %.loc14_13.1, %.loc14_13.2
-// CHECK:STDOUT:   %.loc14_13.4: ref %C = converted @__global_init.%.loc14, %.loc14_13.3
-// CHECK:STDOUT:   %c: ref %C = bind_name c, %.loc14_13.4
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %x.patt: %pattern_type.c39 = binding_pattern x [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %ElementType.ref: type = name_ref ElementType, %ElementType.decl [concrete = constants.%ElementType.e6b]
-// CHECK:STDOUT:   %.loc22: ref %ElementType.e6b = temporary @__global_init.%.loc22_25.2, @__global_init.%At.call
-// CHECK:STDOUT:   %x: ref %ElementType.e6b = bind_name x, %.loc22
+// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [concrete = constants.%F] {} {}
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %C.ref as %IndexWith.type {
-// CHECK:STDOUT:   %At.decl: %At.type.178 = fn_decl @At.2 [concrete = constants.%At.d43] {
-// CHECK:STDOUT:     %self.patt: %pattern_type.c48 = binding_pattern self [concrete]
-// CHECK:STDOUT:     %self.param_patt: %pattern_type.c48 = value_param_pattern %self.patt, call_param0 [concrete]
-// CHECK:STDOUT:     %subscript.patt: %pattern_type.df7 = binding_pattern subscript [concrete]
-// CHECK:STDOUT:     %subscript.param_patt: %pattern_type.df7 = value_param_pattern %subscript.patt, call_param1 [concrete]
-// CHECK:STDOUT:     %return.patt: %pattern_type.c39 = return_slot_pattern [concrete]
-// CHECK:STDOUT:     %return.param_patt: %pattern_type.c39 = out_param_pattern %return.patt, call_param2 [concrete]
+// CHECK:STDOUT: generic interface @IndexWith(imports.%Core.import_ref.5ab3ec.1: type) [from "core_wrong_arg_count.carbon"] {
+// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType (constants.%SubscriptType)]
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic = %IndexWith.type (constants.%IndexWith.type.bd2)]
+// CHECK:STDOUT:   %Self: @IndexWith.%IndexWith.type (%IndexWith.type.bd2) = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self.30a)]
+// CHECK:STDOUT:   %At.type: type = fn_type @At.1, @IndexWith(%SubscriptType) [symbolic = %At.type (constants.%At.type.cf4)]
+// CHECK:STDOUT:   %At: @IndexWith.%At.type (%At.type.cf4) = struct_value () [symbolic = %At (constants.%At.281)]
+// CHECK:STDOUT:   %IndexWith.assoc_type: type = assoc_entity_type @IndexWith, @IndexWith(%SubscriptType) [symbolic = %IndexWith.assoc_type (constants.%IndexWith.assoc_type.290)]
+// CHECK:STDOUT:   %assoc0: @IndexWith.%IndexWith.assoc_type (%IndexWith.assoc_type.290) = assoc_entity element0, imports.%Core.import_ref.e99 [symbolic = %assoc0 (constants.%assoc0.af8)]
+// CHECK:STDOUT:
+// CHECK:STDOUT:   interface {
+// CHECK:STDOUT:   !members:
+// CHECK:STDOUT:     .Self = imports.%Core.import_ref.68a
+// CHECK:STDOUT:     .At = imports.%Core.import_ref.613
+// CHECK:STDOUT:     witness = (imports.%Core.At)
+// CHECK:STDOUT:   }
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %.loc6_7.2 as %IndexWith.type {
+// CHECK:STDOUT:   %At.decl: %At.type.486 = fn_decl @At.2 [concrete = constants.%At.7c4] {
+// CHECK:STDOUT:     %self.patt: %pattern_type.cb1 = binding_pattern self [concrete]
+// CHECK:STDOUT:     %self.param_patt: %pattern_type.cb1 = value_param_pattern %self.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %subscript.patt: %pattern_type.cb1 = binding_pattern subscript [concrete]
+// CHECK:STDOUT:     %subscript.param_patt: %pattern_type.cb1 = value_param_pattern %subscript.patt, call_param1 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.cb1 = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.cb1 = out_param_pattern %return.patt, call_param2 [concrete]
 // CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %ElementType.ref: type = name_ref ElementType, file.%ElementType.decl [concrete = constants.%ElementType.e6b]
-// CHECK:STDOUT:     %self.param: %C = value_param call_param0
-// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.%C.ref [concrete = constants.%C]
-// CHECK:STDOUT:     %self: %C = bind_name self, %self.param
-// CHECK:STDOUT:     %subscript.param: %SubscriptType.8ee = value_param call_param1
-// CHECK:STDOUT:     %SubscriptType.ref: type = name_ref SubscriptType, file.%SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
-// CHECK:STDOUT:     %subscript: %SubscriptType.8ee = bind_name subscript, %subscript.param
-// CHECK:STDOUT:     %return.param: ref %ElementType.e6b = out_param call_param2
-// CHECK:STDOUT:     %return: ref %ElementType.e6b = return_slot %return.param
+// CHECK:STDOUT:     %.loc7_40.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:     %.loc7_40.2: type = converted %.loc7_40.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %self.param: %empty_tuple.type = value_param call_param0
+// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.%.loc6_7.2 [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     %self: %empty_tuple.type = bind_name self, %self.param
+// CHECK:STDOUT:     %subscript.param: %empty_tuple.type = value_param call_param1
+// CHECK:STDOUT:     %.loc7_33.1: type = splice_block %.loc7_33.3 [concrete = constants.%empty_tuple.type] {
+// CHECK:STDOUT:       %.loc7_33.2: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:       %.loc7_33.3: type = converted %.loc7_33.2, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %subscript: %empty_tuple.type = bind_name subscript, %subscript.param
+// CHECK:STDOUT:     %return.param: ref %empty_tuple.type = out_param call_param2
+// CHECK:STDOUT:     %return: ref %empty_tuple.type = return_slot %return.param
 // CHECK:STDOUT:   }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .SubscriptType = <poisoned>
-// CHECK:STDOUT:   .ElementType = <poisoned>
 // CHECK:STDOUT:   .At = %At.decl
 // CHECK:STDOUT:   witness = file.%IndexWith.impl_witness
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: class @C {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT: generic fn @At.1(imports.%Core.import_ref.5ab3ec.2: type, imports.%Core.import_ref.fb5: @IndexWith.%IndexWith.type (%IndexWith.type.bd2)) [from "core_wrong_arg_count.carbon"] {
+// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType (constants.%SubscriptType)]
+// CHECK:STDOUT:   %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic = %IndexWith.type (constants.%IndexWith.type.bd2)]
+// CHECK:STDOUT:   %Self: @At.1.%IndexWith.type (%IndexWith.type.bd2) = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self.30a)]
+// CHECK:STDOUT:   %Self.as_type: type = facet_access_type %Self [symbolic = %Self.as_type (constants.%Self.as_type)]
+// CHECK:STDOUT:   %pattern_type.1: type = pattern_type %Self.as_type [symbolic = %pattern_type.1 (constants.%pattern_type.e1a)]
+// CHECK:STDOUT:   %pattern_type.2: type = pattern_type %SubscriptType [symbolic = %pattern_type.2 (constants.%pattern_type.7dc)]
 // CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%C
+// CHECK:STDOUT:   fn;
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: class @ElementType {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%ElementType.e6b
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: class @SubscriptType {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%SubscriptType.8ee
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @At.2(%self.param: %C, %subscript.param: %SubscriptType.8ee) -> %return.param: %ElementType.e6b {
+// CHECK:STDOUT: fn @At.2(%self.param: %empty_tuple.type, %subscript.param: %empty_tuple.type) -> %empty_tuple.type {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc10_13.1: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %.loc10_13.2: init %ElementType.e6b = class_init (), %return [concrete = constants.%ElementType.val]
-// CHECK:STDOUT:   %.loc10_14: init %ElementType.e6b = converted %.loc10_13.1, %.loc10_13.2 [concrete = constants.%ElementType.val]
-// CHECK:STDOUT:   return %.loc10_14 to %return
+// CHECK:STDOUT:   %.loc8_13: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %empty_tuple: %empty_tuple.type = tuple_value () [concrete = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc8_14: %empty_tuple.type = converted %.loc8_13, %empty_tuple [concrete = constants.%empty_tuple]
+// CHECK:STDOUT:   return %.loc8_14
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: fn @F() {
 // CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc14: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %c.ref: ref %C = name_ref c, file.%c
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
-// CHECK:STDOUT:   %.loc22_25.1: %SubscriptType.8ee = converted %int_0, <error> [concrete = <error>]
-// CHECK:STDOUT:   %impl.elem0: %.d94 = impl_witness_access constants.%IndexWith.impl_witness, element0 [concrete = constants.%At.d43]
-// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %c.ref, %impl.elem0
-// CHECK:STDOUT:   %.loc22_25.2: ref %ElementType.e6b = temporary_storage
-// CHECK:STDOUT:   %.loc22_22: %C = bind_value %c.ref
-// CHECK:STDOUT:   %At.call: init %ElementType.e6b = call %bound_method(%.loc22_22, <error>) to %.loc22_25.2
+// CHECK:STDOUT:   %.loc12_11.1: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %.loc12_14: %empty_tuple.type = tuple_literal ()
+// CHECK:STDOUT:   %empty_tuple.loc12_11: %empty_tuple.type = tuple_value () [concrete = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc12_11.2: %empty_tuple.type = converted %.loc12_11.1, %empty_tuple.loc12_11 [concrete = constants.%empty_tuple]
+// CHECK:STDOUT:   %empty_tuple.loc12_14: %empty_tuple.type = tuple_value () [concrete = constants.%empty_tuple]
+// CHECK:STDOUT:   %.loc12_15: %empty_tuple.type = converted %.loc12_14, %empty_tuple.loc12_14 [concrete = constants.%empty_tuple]
+// CHECK:STDOUT:   %impl.elem0: %.ffc = impl_witness_access constants.%IndexWith.impl_witness, element0 [concrete = constants.%At.7c4]
+// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %.loc12_11.2, %impl.elem0 [concrete = constants.%At.bound]
+// CHECK:STDOUT:   %At.call: init %empty_tuple.type = call %bound_method(%.loc12_11.2, %.loc12_15)
 // CHECK:STDOUT:   return
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_index_with_not_implemented.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %C: type = class_type @C [concrete]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %complete_type.357: <witness> = complete_type_witness %empty_struct_type [concrete]
-// CHECK:STDOUT:   %pattern_type.c48: type = pattern_type %C [concrete]
-// CHECK:STDOUT:   %C.val: %C = struct_value () [concrete]
-// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
-// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
-// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
-// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
-// CHECK:STDOUT:   %pattern_type.7ce: type = pattern_type %i32 [concrete]
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
-// CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
-// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
+// CHECK:STDOUT: specific @IndexWith(constants.%SubscriptType) {
+// CHECK:STDOUT:   %SubscriptType => constants.%SubscriptType
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
-// CHECK:STDOUT:     .Int = %Core.Int
-// CHECK:STDOUT:     .IndexWith = %Core.IndexWith
-// CHECK:STDOUT:     import Core//prelude
-// CHECK:STDOUT:     import Core//prelude/...
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/types/int, Int, loaded [concrete = constants.%Int.generic]
-// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//prelude/operators/index, IndexWith, loaded [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT: specific @At.1(constants.%SubscriptType, constants.%Self.30a) {
+// CHECK:STDOUT:   %SubscriptType => constants.%SubscriptType
+// CHECK:STDOUT:   %IndexWith.type => constants.%IndexWith.type.bd2
+// CHECK:STDOUT:   %Self => constants.%Self.30a
+// CHECK:STDOUT:   %Self.as_type => constants.%Self.as_type
+// CHECK:STDOUT:   %pattern_type.1 => constants.%pattern_type.e1a
+// CHECK:STDOUT:   %pattern_type.2 => constants.%pattern_type.7dc
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .Core = imports.%Core
-// CHECK:STDOUT:     .C = %C.decl
-// CHECK:STDOUT:     .c = %c
-// CHECK:STDOUT:     .x = %x
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.import = import Core
-// CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %c.patt: %pattern_type.c48 = binding_pattern c [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %C.ref: type = name_ref C, %C.decl [concrete = constants.%C]
-// CHECK:STDOUT:   %.loc6_13.1: ref %C = temporary_storage
-// CHECK:STDOUT:   %.loc6_13.2: init %C = class_init (), %.loc6_13.1 [concrete = constants.%C.val]
-// CHECK:STDOUT:   %.loc6_13.3: ref %C = temporary %.loc6_13.1, %.loc6_13.2
-// CHECK:STDOUT:   %.loc6_13.4: ref %C = converted @__global_init.%.loc6, %.loc6_13.3
-// CHECK:STDOUT:   %c: ref %C = bind_name c, %.loc6_13.4
-// CHECK:STDOUT:   name_binding_decl {
-// CHECK:STDOUT:     %x.patt: %pattern_type.7ce = binding_pattern x [concrete]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %.loc11: type = splice_block %i32 [concrete = constants.%i32] {
-// CHECK:STDOUT:     %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
-// CHECK:STDOUT:     %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %x: %i32 = bind_name x, <error> [concrete = <error>]
+// CHECK:STDOUT: specific @IndexWith(constants.%empty_tuple.type) {
+// CHECK:STDOUT:   %SubscriptType => constants.%empty_tuple.type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !definition:
+// CHECK:STDOUT:   %IndexWith.type => constants.%IndexWith.type.a51
+// CHECK:STDOUT:   %Self => constants.%Self.8f0
+// CHECK:STDOUT:   %At.type => constants.%At.type.969
+// CHECK:STDOUT:   %At => constants.%At.9b9
+// CHECK:STDOUT:   %IndexWith.assoc_type => constants.%IndexWith.assoc_type.3d4
+// CHECK:STDOUT:   %assoc0 => constants.%assoc0.21b
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: class @C {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type.357]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%C
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @__global_init() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc6: %empty_struct_type = struct_literal ()
-// CHECK:STDOUT:   %c.ref: ref %C = name_ref c, file.%c
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
-// CHECK:STDOUT:   return
+// CHECK:STDOUT: specific @At.1(constants.%empty_tuple.type, constants.%IndexWith.facet) {
+// CHECK:STDOUT:   %SubscriptType => constants.%empty_tuple.type
+// CHECK:STDOUT:   %IndexWith.type => constants.%IndexWith.type.a51
+// CHECK:STDOUT:   %Self => constants.%IndexWith.facet
+// CHECK:STDOUT:   %Self.as_type => constants.%empty_tuple.type
+// CHECK:STDOUT:   %pattern_type.1 => constants.%pattern_type.cb1
+// CHECK:STDOUT:   %pattern_type.2 => constants.%pattern_type.cb1
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/overloaded/index_with_prelude.carbon b/toolchain/check/testdata/operators/overloaded/index_with_prelude.carbon
new file mode 100644
index 000000000000..b66361aaf644
--- /dev/null
+++ b/toolchain/check/testdata/operators/overloaded/index_with_prelude.carbon
@@ -0,0 +1,656 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
+// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/operators/overloaded/index_with_prelude.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/operators/overloaded/index_with_prelude.carbon
+
+// --- overloaded_index.carbon
+
+library "[[@TEST_NAME]]";
+
+class C {}
+class ElementType {}
+class SubscriptType {}
+
+impl C as Core.IndexWith(SubscriptType, ElementType) {
+  fn At[self: Self](subscript: SubscriptType) -> ElementType {
+    return {};
+  }
+}
+
+let s: SubscriptType = {};
+let c: C = {};
+let x: ElementType = c[s];
+
+// --- overloaded_builtin.carbon
+
+library "[[@TEST_NAME]]";
+
+impl (i32, i32) as Core.IndexWith(i32, i32) {
+  fn At[self: Self](subscript: i32) -> i32 {
+    return self.0;
+  }
+}
+
+let s: (i32, i32) = (1, 5);
+let e: i32 = s[0];
+
+// --- fail_invalid_subscript_type.carbon
+
+library "[[@TEST_NAME]]";
+
+class C { }
+class ElementType {}
+class SubscriptType {}
+
+impl C as Core.IndexWith(SubscriptType, ElementType) {
+  fn At[self: Self](subscript: SubscriptType) -> ElementType {
+    return {};
+  }
+}
+
+let c: C = {};
+// CHECK:STDERR: fail_invalid_subscript_type.carbon:[[@LINE+7]]:22: error: cannot implicitly convert expression of type `Core.IntLiteral` to `SubscriptType` [ConversionFailure]
+// CHECK:STDERR: let x: ElementType = c[0];
+// CHECK:STDERR:                      ^~~~
+// CHECK:STDERR: fail_invalid_subscript_type.carbon:[[@LINE+4]]:22: note: type `Core.IntLiteral` does not implement interface `Core.ImplicitAs(SubscriptType)` [MissingImplInMemberAccessNote]
+// CHECK:STDERR: let x: ElementType = c[0];
+// CHECK:STDERR:                      ^~~~
+// CHECK:STDERR:
+let x: ElementType = c[0];
+
+// --- fail_index_with_not_implemented.carbon
+
+library "[[@TEST_NAME]]";
+
+class C { }
+
+let c: C = {};
+// CHECK:STDERR: fail_index_with_not_implemented.carbon:[[@LINE+4]]:14: error: type `C` does not support indexing [TypeNotIndexable]
+// CHECK:STDERR: let x: i32 = c[0];
+// CHECK:STDERR:              ^~~~
+// CHECK:STDERR:
+let x: i32 = c[0];
+
+
+// CHECK:STDOUT: --- overloaded_index.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
+// CHECK:STDOUT:   %ElementType.e6b: type = class_type @ElementType [concrete]
+// CHECK:STDOUT:   %SubscriptType.8ee: type = class_type @SubscriptType [concrete]
+// CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
+// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.type.e80: type = facet_type <@IndexWith, @IndexWith(%SubscriptType.8ee, %ElementType.e6b)> [concrete]
+// CHECK:STDOUT:   %At.type.b3f: type = fn_type @At.1, @IndexWith(%SubscriptType.8ee, %ElementType.e6b) [concrete]
+// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness file.%IndexWith.impl_witness_table [concrete]
+// CHECK:STDOUT:   %pattern_type.c48: type = pattern_type %C [concrete]
+// CHECK:STDOUT:   %pattern_type.df7: type = pattern_type %SubscriptType.8ee [concrete]
+// CHECK:STDOUT:   %pattern_type.c39: type = pattern_type %ElementType.e6b [concrete]
+// CHECK:STDOUT:   %At.type.178: type = fn_type @At.2 [concrete]
+// CHECK:STDOUT:   %At.d43: %At.type.178 = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.facet: %IndexWith.type.e80 = facet_value %C, (%IndexWith.impl_witness) [concrete]
+// CHECK:STDOUT:   %ElementType.val: %ElementType.e6b = struct_value () [concrete]
+// CHECK:STDOUT:   %SubscriptType.val: %SubscriptType.8ee = struct_value () [concrete]
+// CHECK:STDOUT:   %C.val: %C = struct_value () [concrete]
+// CHECK:STDOUT:   %.d94: type = fn_type_with_self_type %At.type.b3f, %IndexWith.facet [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .IndexWith = %Core.IndexWith
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//prelude/operators/index, IndexWith, loaded [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .C = %C.decl
+// CHECK:STDOUT:     .ElementType = %ElementType.decl
+// CHECK:STDOUT:     .SubscriptType = %SubscriptType.decl
+// CHECK:STDOUT:     .s = %s
+// CHECK:STDOUT:     .c = %c
+// CHECK:STDOUT:     .x = %x
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
+// CHECK:STDOUT:   %ElementType.decl: type = class_decl @ElementType [concrete = constants.%ElementType.e6b] {} {}
+// CHECK:STDOUT:   %SubscriptType.decl: type = class_decl @SubscriptType [concrete = constants.%SubscriptType.8ee] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %C.ref: type = name_ref C, file.%C.decl [concrete = constants.%C]
+// CHECK:STDOUT:     %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
+// CHECK:STDOUT:     %IndexWith.ref: %IndexWith.type.504 = name_ref IndexWith, imports.%Core.IndexWith [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT:     %SubscriptType.ref: type = name_ref SubscriptType, file.%SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
+// CHECK:STDOUT:     %ElementType.ref: type = name_ref ElementType, file.%ElementType.decl [concrete = constants.%ElementType.e6b]
+// CHECK:STDOUT:     %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(constants.%SubscriptType.8ee, constants.%ElementType.e6b)> [concrete = constants.%IndexWith.type.e80]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %IndexWith.impl_witness_table = impl_witness_table (@impl.%At.decl), @impl [concrete]
+// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness %IndexWith.impl_witness_table [concrete = constants.%IndexWith.impl_witness]
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %s.patt: %pattern_type.df7 = binding_pattern s [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %SubscriptType.ref: type = name_ref SubscriptType, %SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
+// CHECK:STDOUT:   %.loc14_25.1: ref %SubscriptType.8ee = temporary_storage
+// CHECK:STDOUT:   %.loc14_25.2: init %SubscriptType.8ee = class_init (), %.loc14_25.1 [concrete = constants.%SubscriptType.val]
+// CHECK:STDOUT:   %.loc14_25.3: ref %SubscriptType.8ee = temporary %.loc14_25.1, %.loc14_25.2
+// CHECK:STDOUT:   %.loc14_25.4: ref %SubscriptType.8ee = converted @__global_init.%.loc14, %.loc14_25.3
+// CHECK:STDOUT:   %s: ref %SubscriptType.8ee = bind_name s, %.loc14_25.4
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %c.patt: %pattern_type.c48 = binding_pattern c [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %C.ref: type = name_ref C, %C.decl [concrete = constants.%C]
+// CHECK:STDOUT:   %.loc15_13.1: ref %C = temporary_storage
+// CHECK:STDOUT:   %.loc15_13.2: init %C = class_init (), %.loc15_13.1 [concrete = constants.%C.val]
+// CHECK:STDOUT:   %.loc15_13.3: ref %C = temporary %.loc15_13.1, %.loc15_13.2
+// CHECK:STDOUT:   %.loc15_13.4: ref %C = converted @__global_init.%.loc15, %.loc15_13.3
+// CHECK:STDOUT:   %c: ref %C = bind_name c, %.loc15_13.4
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %x.patt: %pattern_type.c39 = binding_pattern x [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %ElementType.ref: type = name_ref ElementType, %ElementType.decl [concrete = constants.%ElementType.e6b]
+// CHECK:STDOUT:   %.loc16: ref %ElementType.e6b = temporary @__global_init.%.loc16_25, @__global_init.%At.call
+// CHECK:STDOUT:   %x: ref %ElementType.e6b = bind_name x, %.loc16
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %C.ref as %IndexWith.type {
+// CHECK:STDOUT:   %At.decl: %At.type.178 = fn_decl @At.2 [concrete = constants.%At.d43] {
+// CHECK:STDOUT:     %self.patt: %pattern_type.c48 = binding_pattern self [concrete]
+// CHECK:STDOUT:     %self.param_patt: %pattern_type.c48 = value_param_pattern %self.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %subscript.patt: %pattern_type.df7 = binding_pattern subscript [concrete]
+// CHECK:STDOUT:     %subscript.param_patt: %pattern_type.df7 = value_param_pattern %subscript.patt, call_param1 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.c39 = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.c39 = out_param_pattern %return.patt, call_param2 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %ElementType.ref: type = name_ref ElementType, file.%ElementType.decl [concrete = constants.%ElementType.e6b]
+// CHECK:STDOUT:     %self.param: %C = value_param call_param0
+// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.%C.ref [concrete = constants.%C]
+// CHECK:STDOUT:     %self: %C = bind_name self, %self.param
+// CHECK:STDOUT:     %subscript.param: %SubscriptType.8ee = value_param call_param1
+// CHECK:STDOUT:     %SubscriptType.ref: type = name_ref SubscriptType, file.%SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
+// CHECK:STDOUT:     %subscript: %SubscriptType.8ee = bind_name subscript, %subscript.param
+// CHECK:STDOUT:     %return.param: ref %ElementType.e6b = out_param call_param2
+// CHECK:STDOUT:     %return: ref %ElementType.e6b = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .SubscriptType = <poisoned>
+// CHECK:STDOUT:   .ElementType = <poisoned>
+// CHECK:STDOUT:   .At = %At.decl
+// CHECK:STDOUT:   witness = file.%IndexWith.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%C
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @ElementType {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%ElementType.e6b
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @SubscriptType {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%SubscriptType.8ee
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @At.2(%self.param: %C, %subscript.param: %SubscriptType.8ee) -> %return.param: %ElementType.e6b {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc10_13.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc10_13.2: init %ElementType.e6b = class_init (), %return [concrete = constants.%ElementType.val]
+// CHECK:STDOUT:   %.loc10_14: init %ElementType.e6b = converted %.loc10_13.1, %.loc10_13.2 [concrete = constants.%ElementType.val]
+// CHECK:STDOUT:   return %.loc10_14 to %return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc14: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc15: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %c.ref: ref %C = name_ref c, file.%c
+// CHECK:STDOUT:   %s.ref: ref %SubscriptType.8ee = name_ref s, file.%s
+// CHECK:STDOUT:   %.loc16_24: %SubscriptType.8ee = bind_value %s.ref
+// CHECK:STDOUT:   %impl.elem0: %.d94 = impl_witness_access constants.%IndexWith.impl_witness, element0 [concrete = constants.%At.d43]
+// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %c.ref, %impl.elem0
+// CHECK:STDOUT:   %.loc16_25: ref %ElementType.e6b = temporary_storage
+// CHECK:STDOUT:   %.loc16_22: %C = bind_value %c.ref
+// CHECK:STDOUT:   %At.call: init %ElementType.e6b = call %bound_method(%.loc16_22, %.loc16_24) to %.loc16_25
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- overloaded_builtin.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
+// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
+// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
+// CHECK:STDOUT:   %tuple.type.24b: type = tuple_type (type, type) [concrete]
+// CHECK:STDOUT:   %tuple.type.d07: type = tuple_type (%i32, %i32) [concrete]
+// CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
+// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.type.917: type = facet_type <@IndexWith, @IndexWith(%i32, %i32)> [concrete]
+// CHECK:STDOUT:   %At.type.d77: type = fn_type @At.1, @IndexWith(%i32, %i32) [concrete]
+// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness file.%IndexWith.impl_witness_table [concrete]
+// CHECK:STDOUT:   %pattern_type.511: type = pattern_type %tuple.type.d07 [concrete]
+// CHECK:STDOUT:   %pattern_type.7ce: type = pattern_type %i32 [concrete]
+// CHECK:STDOUT:   %At.type.9ac: type = fn_type @At.2 [concrete]
+// CHECK:STDOUT:   %At.642: %At.type.9ac = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.facet: %IndexWith.type.917 = facet_value %tuple.type.d07, (%IndexWith.impl_witness) [concrete]
+// CHECK:STDOUT:   %int_0.5c6: Core.IntLiteral = int_value 0 [concrete]
+// CHECK:STDOUT:   %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
+// CHECK:STDOUT:   %int_5.64b: Core.IntLiteral = int_value 5 [concrete]
+// CHECK:STDOUT:   %tuple.type.f94: type = tuple_type (Core.IntLiteral, Core.IntLiteral) [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
+// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.205: type = facet_type <@ImplicitAs, @ImplicitAs(%i32)> [concrete]
+// CHECK:STDOUT:   %Convert.type.1b6: type = fn_type @Convert.1, @ImplicitAs(%i32) [concrete]
+// CHECK:STDOUT:   %To.c80: Core.IntLiteral = bind_symbolic_name To, 0 [symbolic]
+// CHECK:STDOUT:   %Convert.type.0f9: type = fn_type @Convert.2, @impl.4f9(%To.c80) [symbolic]
+// CHECK:STDOUT:   %Convert.f06: %Convert.type.0f9 = struct_value () [symbolic]
+// CHECK:STDOUT:   %ImplicitAs.impl_witness.c75: <witness> = impl_witness imports.%ImplicitAs.impl_witness_table.a2f, @impl.4f9(%int_32) [concrete]
+// CHECK:STDOUT:   %Convert.type.035: type = fn_type @Convert.2, @impl.4f9(%int_32) [concrete]
+// CHECK:STDOUT:   %Convert.956: %Convert.type.035 = struct_value () [concrete]
+// CHECK:STDOUT:   %ImplicitAs.facet: %ImplicitAs.type.205 = facet_value Core.IntLiteral, (%ImplicitAs.impl_witness.c75) [concrete]
+// CHECK:STDOUT:   %.9c3: type = fn_type_with_self_type %Convert.type.1b6, %ImplicitAs.facet [concrete]
+// CHECK:STDOUT:   %Convert.bound.ab5: <bound method> = bound_method %int_1.5b8, %Convert.956 [concrete]
+// CHECK:STDOUT:   %Convert.specific_fn: <specific function> = specific_function %Convert.956, @Convert.2(%int_32) [concrete]
+// CHECK:STDOUT:   %bound_method.9a1: <bound method> = bound_method %int_1.5b8, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_1.5d2: %i32 = int_value 1 [concrete]
+// CHECK:STDOUT:   %Convert.bound.4e6: <bound method> = bound_method %int_5.64b, %Convert.956 [concrete]
+// CHECK:STDOUT:   %bound_method.a25: <bound method> = bound_method %int_5.64b, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_5.0f6: %i32 = int_value 5 [concrete]
+// CHECK:STDOUT:   %tuple: %tuple.type.d07 = tuple_value (%int_1.5d2, %int_5.0f6) [concrete]
+// CHECK:STDOUT:   %Convert.bound.d04: <bound method> = bound_method %int_0.5c6, %Convert.956 [concrete]
+// CHECK:STDOUT:   %bound_method.b6e: <bound method> = bound_method %int_0.5c6, %Convert.specific_fn [concrete]
+// CHECK:STDOUT:   %int_0.6a9: %i32 = int_value 0 [concrete]
+// CHECK:STDOUT:   %.2dc: type = fn_type_with_self_type %At.type.d77, %IndexWith.facet [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .Int = %Core.Int
+// CHECK:STDOUT:     .IndexWith = %Core.IndexWith
+// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/types/int, Int, loaded [concrete = constants.%Int.generic]
+// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//prelude/operators/index, IndexWith, loaded [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/operators/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
+// CHECK:STDOUT:   %Core.import_ref.a5b: @impl.4f9.%Convert.type (%Convert.type.0f9) = import_ref Core//prelude/types/int, loc19_39, loaded [symbolic = @impl.4f9.%Convert (constants.%Convert.f06)]
+// CHECK:STDOUT:   %ImplicitAs.impl_witness_table.a2f = impl_witness_table (%Core.import_ref.a5b), @impl.4f9 [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .s = %s
+// CHECK:STDOUT:     .e = %e
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   impl_decl @impl.18b [concrete] {} {
+// CHECK:STDOUT:     %int_32.loc4_7: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc4_7: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %int_32.loc4_12: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc4_12: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %.loc4_15.1: %tuple.type.24b = tuple_literal (%i32.loc4_7, %i32.loc4_12)
+// CHECK:STDOUT:     %.loc4_15.2: type = converted %.loc4_15.1, constants.%tuple.type.d07 [concrete = constants.%tuple.type.d07]
+// CHECK:STDOUT:     %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
+// CHECK:STDOUT:     %IndexWith.ref: %IndexWith.type.504 = name_ref IndexWith, imports.%Core.IndexWith [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT:     %int_32.loc4_35: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc4_35: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %int_32.loc4_40: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc4_40: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(constants.%i32, constants.%i32)> [concrete = constants.%IndexWith.type.917]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %IndexWith.impl_witness_table = impl_witness_table (@impl.18b.%At.decl), @impl.18b [concrete]
+// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness %IndexWith.impl_witness_table [concrete = constants.%IndexWith.impl_witness]
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %s.patt: %pattern_type.511 = binding_pattern s [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %.loc10_17.1: type = splice_block %.loc10_17.3 [concrete = constants.%tuple.type.d07] {
+// CHECK:STDOUT:     %int_32.loc10_9: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc10_9: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %int_32.loc10_14: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc10_14: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %.loc10_17.2: %tuple.type.24b = tuple_literal (%i32.loc10_9, %i32.loc10_14)
+// CHECK:STDOUT:     %.loc10_17.3: type = converted %.loc10_17.2, constants.%tuple.type.d07 [concrete = constants.%tuple.type.d07]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %impl.elem0.loc10_26.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:   %bound_method.loc10_26.1: <bound method> = bound_method @__global_init.%int_1, %impl.elem0.loc10_26.1 [concrete = constants.%Convert.bound.ab5]
+// CHECK:STDOUT:   %specific_fn.loc10_26.1: <specific function> = specific_function %impl.elem0.loc10_26.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:   %bound_method.loc10_26.2: <bound method> = bound_method @__global_init.%int_1, %specific_fn.loc10_26.1 [concrete = constants.%bound_method.9a1]
+// CHECK:STDOUT:   %int.convert_checked.loc10_26.1: init %i32 = call %bound_method.loc10_26.2(@__global_init.%int_1) [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc10_26.1: %i32 = value_of_initializer %int.convert_checked.loc10_26.1 [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:   %.loc10_26.2: %i32 = converted @__global_init.%int_1, %.loc10_26.1 [concrete = constants.%int_1.5d2]
+// CHECK:STDOUT:   %impl.elem0.loc10_26.2: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:   %bound_method.loc10_26.3: <bound method> = bound_method @__global_init.%int_5, %impl.elem0.loc10_26.2 [concrete = constants.%Convert.bound.4e6]
+// CHECK:STDOUT:   %specific_fn.loc10_26.2: <specific function> = specific_function %impl.elem0.loc10_26.2, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:   %bound_method.loc10_26.4: <bound method> = bound_method @__global_init.%int_5, %specific_fn.loc10_26.2 [concrete = constants.%bound_method.a25]
+// CHECK:STDOUT:   %int.convert_checked.loc10_26.2: init %i32 = call %bound_method.loc10_26.4(@__global_init.%int_5) [concrete = constants.%int_5.0f6]
+// CHECK:STDOUT:   %.loc10_26.3: %i32 = value_of_initializer %int.convert_checked.loc10_26.2 [concrete = constants.%int_5.0f6]
+// CHECK:STDOUT:   %.loc10_26.4: %i32 = converted @__global_init.%int_5, %.loc10_26.3 [concrete = constants.%int_5.0f6]
+// CHECK:STDOUT:   %tuple: %tuple.type.d07 = tuple_value (%.loc10_26.2, %.loc10_26.4) [concrete = constants.%tuple]
+// CHECK:STDOUT:   %.loc10_26.5: %tuple.type.d07 = converted @__global_init.%.loc10, %tuple [concrete = constants.%tuple]
+// CHECK:STDOUT:   %s: %tuple.type.d07 = bind_name s, %.loc10_26.5
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %e.patt: %pattern_type.7ce = binding_pattern e [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %.loc11_8: type = splice_block %i32.loc11 [concrete = constants.%i32] {
+// CHECK:STDOUT:     %int_32.loc11: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc11: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %.loc11_17.1: ref %i32 = temporary_storage
+// CHECK:STDOUT:   %.loc11_17.2: ref %i32 = temporary %.loc11_17.1, @__global_init.%At.call
+// CHECK:STDOUT:   %e: ref %i32 = bind_name e, %.loc11_17.2
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl.18b: %.loc4_15.2 as %IndexWith.type {
+// CHECK:STDOUT:   %At.decl: %At.type.9ac = fn_decl @At.2 [concrete = constants.%At.642] {
+// CHECK:STDOUT:     %self.patt: %pattern_type.511 = binding_pattern self [concrete]
+// CHECK:STDOUT:     %self.param_patt: %pattern_type.511 = value_param_pattern %self.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %subscript.patt: %pattern_type.7ce = binding_pattern subscript [concrete]
+// CHECK:STDOUT:     %subscript.param_patt: %pattern_type.7ce = value_param_pattern %subscript.patt, call_param1 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.7ce = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.7ce = out_param_pattern %return.patt, call_param2 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %int_32.loc5_40: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32.loc5_40: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     %self.param: %tuple.type.d07 = value_param call_param0
+// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.18b.%.loc4_15.2 [concrete = constants.%tuple.type.d07]
+// CHECK:STDOUT:     %self: %tuple.type.d07 = bind_name self, %self.param
+// CHECK:STDOUT:     %subscript.param: %i32 = value_param call_param1
+// CHECK:STDOUT:     %.loc5: type = splice_block %i32.loc5_32 [concrete = constants.%i32] {
+// CHECK:STDOUT:       %int_32.loc5_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:       %i32.loc5_32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:     }
+// CHECK:STDOUT:     %subscript: %i32 = bind_name subscript, %subscript.param
+// CHECK:STDOUT:     %return.param: ref %i32 = out_param call_param2
+// CHECK:STDOUT:     %return: ref %i32 = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .At = %At.decl
+// CHECK:STDOUT:   witness = file.%IndexWith.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @At.2(%self.param: %tuple.type.d07, %subscript.param: %i32) -> %i32 {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %self.ref: %tuple.type.d07 = name_ref self, %self
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0.5c6]
+// CHECK:STDOUT:   %tuple.elem0: %i32 = tuple_access %self.ref, element0
+// CHECK:STDOUT:   return %tuple.elem0
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
+// CHECK:STDOUT:   %int_5: Core.IntLiteral = int_value 5 [concrete = constants.%int_5.64b]
+// CHECK:STDOUT:   %.loc10: %tuple.type.f94 = tuple_literal (%int_1, %int_5)
+// CHECK:STDOUT:   %s.ref: %tuple.type.d07 = name_ref s, file.%s
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0.5c6]
+// CHECK:STDOUT:   %impl.elem0.loc11_17.1: %.9c3 = impl_witness_access constants.%ImplicitAs.impl_witness.c75, element0 [concrete = constants.%Convert.956]
+// CHECK:STDOUT:   %bound_method.loc11_17.1: <bound method> = bound_method %int_0, %impl.elem0.loc11_17.1 [concrete = constants.%Convert.bound.d04]
+// CHECK:STDOUT:   %specific_fn: <specific function> = specific_function %impl.elem0.loc11_17.1, @Convert.2(constants.%int_32) [concrete = constants.%Convert.specific_fn]
+// CHECK:STDOUT:   %bound_method.loc11_17.2: <bound method> = bound_method %int_0, %specific_fn [concrete = constants.%bound_method.b6e]
+// CHECK:STDOUT:   %int.convert_checked: init %i32 = call %bound_method.loc11_17.2(%int_0) [concrete = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc11_17.1: %i32 = value_of_initializer %int.convert_checked [concrete = constants.%int_0.6a9]
+// CHECK:STDOUT:   %.loc11_17.2: %i32 = converted %int_0, %.loc11_17.1 [concrete = constants.%int_0.6a9]
+// CHECK:STDOUT:   %impl.elem0.loc11_17.2: %.2dc = impl_witness_access constants.%IndexWith.impl_witness, element0 [concrete = constants.%At.642]
+// CHECK:STDOUT:   %bound_method.loc11_17.3: <bound method> = bound_method %s.ref, %impl.elem0.loc11_17.2
+// CHECK:STDOUT:   %At.call: init %i32 = call %bound_method.loc11_17.3(%s.ref, %.loc11_17.2)
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_invalid_subscript_type.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
+// CHECK:STDOUT:   %ElementType.e6b: type = class_type @ElementType [concrete]
+// CHECK:STDOUT:   %SubscriptType.8ee: type = class_type @SubscriptType [concrete]
+// CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
+// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.type.e80: type = facet_type <@IndexWith, @IndexWith(%SubscriptType.8ee, %ElementType.e6b)> [concrete]
+// CHECK:STDOUT:   %At.type.b3f: type = fn_type @At.1, @IndexWith(%SubscriptType.8ee, %ElementType.e6b) [concrete]
+// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness file.%IndexWith.impl_witness_table [concrete]
+// CHECK:STDOUT:   %pattern_type.c48: type = pattern_type %C [concrete]
+// CHECK:STDOUT:   %pattern_type.df7: type = pattern_type %SubscriptType.8ee [concrete]
+// CHECK:STDOUT:   %pattern_type.c39: type = pattern_type %ElementType.e6b [concrete]
+// CHECK:STDOUT:   %At.type.178: type = fn_type @At.2 [concrete]
+// CHECK:STDOUT:   %At.d43: %At.type.178 = struct_value () [concrete]
+// CHECK:STDOUT:   %IndexWith.facet: %IndexWith.type.e80 = facet_value %C, (%IndexWith.impl_witness) [concrete]
+// CHECK:STDOUT:   %ElementType.val: %ElementType.e6b = struct_value () [concrete]
+// CHECK:STDOUT:   %C.val: %C = struct_value () [concrete]
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
+// CHECK:STDOUT:   %ImplicitAs.type.cc7: type = generic_interface_type @ImplicitAs [concrete]
+// CHECK:STDOUT:   %ImplicitAs.generic: %ImplicitAs.type.cc7 = struct_value () [concrete]
+// CHECK:STDOUT:   %.d94: type = fn_type_with_self_type %At.type.b3f, %IndexWith.facet [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .IndexWith = %Core.IndexWith
+// CHECK:STDOUT:     .ImplicitAs = %Core.ImplicitAs
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//prelude/operators/index, IndexWith, loaded [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT:   %Core.ImplicitAs: %ImplicitAs.type.cc7 = import_ref Core//prelude/operators/as, ImplicitAs, loaded [concrete = constants.%ImplicitAs.generic]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .C = %C.decl
+// CHECK:STDOUT:     .ElementType = %ElementType.decl
+// CHECK:STDOUT:     .SubscriptType = %SubscriptType.decl
+// CHECK:STDOUT:     .c = %c
+// CHECK:STDOUT:     .x = %x
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
+// CHECK:STDOUT:   %ElementType.decl: type = class_decl @ElementType [concrete = constants.%ElementType.e6b] {} {}
+// CHECK:STDOUT:   %SubscriptType.decl: type = class_decl @SubscriptType [concrete = constants.%SubscriptType.8ee] {} {}
+// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
+// CHECK:STDOUT:     %C.ref: type = name_ref C, file.%C.decl [concrete = constants.%C]
+// CHECK:STDOUT:     %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
+// CHECK:STDOUT:     %IndexWith.ref: %IndexWith.type.504 = name_ref IndexWith, imports.%Core.IndexWith [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT:     %SubscriptType.ref: type = name_ref SubscriptType, file.%SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
+// CHECK:STDOUT:     %ElementType.ref: type = name_ref ElementType, file.%ElementType.decl [concrete = constants.%ElementType.e6b]
+// CHECK:STDOUT:     %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(constants.%SubscriptType.8ee, constants.%ElementType.e6b)> [concrete = constants.%IndexWith.type.e80]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %IndexWith.impl_witness_table = impl_witness_table (@impl.%At.decl), @impl [concrete]
+// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness %IndexWith.impl_witness_table [concrete = constants.%IndexWith.impl_witness]
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %c.patt: %pattern_type.c48 = binding_pattern c [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %C.ref: type = name_ref C, %C.decl [concrete = constants.%C]
+// CHECK:STDOUT:   %.loc14_13.1: ref %C = temporary_storage
+// CHECK:STDOUT:   %.loc14_13.2: init %C = class_init (), %.loc14_13.1 [concrete = constants.%C.val]
+// CHECK:STDOUT:   %.loc14_13.3: ref %C = temporary %.loc14_13.1, %.loc14_13.2
+// CHECK:STDOUT:   %.loc14_13.4: ref %C = converted @__global_init.%.loc14, %.loc14_13.3
+// CHECK:STDOUT:   %c: ref %C = bind_name c, %.loc14_13.4
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %x.patt: %pattern_type.c39 = binding_pattern x [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %ElementType.ref: type = name_ref ElementType, %ElementType.decl [concrete = constants.%ElementType.e6b]
+// CHECK:STDOUT:   %.loc22: ref %ElementType.e6b = temporary @__global_init.%.loc22_25.2, @__global_init.%At.call
+// CHECK:STDOUT:   %x: ref %ElementType.e6b = bind_name x, %.loc22
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: impl @impl: %C.ref as %IndexWith.type {
+// CHECK:STDOUT:   %At.decl: %At.type.178 = fn_decl @At.2 [concrete = constants.%At.d43] {
+// CHECK:STDOUT:     %self.patt: %pattern_type.c48 = binding_pattern self [concrete]
+// CHECK:STDOUT:     %self.param_patt: %pattern_type.c48 = value_param_pattern %self.patt, call_param0 [concrete]
+// CHECK:STDOUT:     %subscript.patt: %pattern_type.df7 = binding_pattern subscript [concrete]
+// CHECK:STDOUT:     %subscript.param_patt: %pattern_type.df7 = value_param_pattern %subscript.patt, call_param1 [concrete]
+// CHECK:STDOUT:     %return.patt: %pattern_type.c39 = return_slot_pattern [concrete]
+// CHECK:STDOUT:     %return.param_patt: %pattern_type.c39 = out_param_pattern %return.patt, call_param2 [concrete]
+// CHECK:STDOUT:   } {
+// CHECK:STDOUT:     %ElementType.ref: type = name_ref ElementType, file.%ElementType.decl [concrete = constants.%ElementType.e6b]
+// CHECK:STDOUT:     %self.param: %C = value_param call_param0
+// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.%C.ref [concrete = constants.%C]
+// CHECK:STDOUT:     %self: %C = bind_name self, %self.param
+// CHECK:STDOUT:     %subscript.param: %SubscriptType.8ee = value_param call_param1
+// CHECK:STDOUT:     %SubscriptType.ref: type = name_ref SubscriptType, file.%SubscriptType.decl [concrete = constants.%SubscriptType.8ee]
+// CHECK:STDOUT:     %subscript: %SubscriptType.8ee = bind_name subscript, %subscript.param
+// CHECK:STDOUT:     %return.param: ref %ElementType.e6b = out_param call_param2
+// CHECK:STDOUT:     %return: ref %ElementType.e6b = return_slot %return.param
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .SubscriptType = <poisoned>
+// CHECK:STDOUT:   .ElementType = <poisoned>
+// CHECK:STDOUT:   .At = %At.decl
+// CHECK:STDOUT:   witness = file.%IndexWith.impl_witness
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%C
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @ElementType {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%ElementType.e6b
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @SubscriptType {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%SubscriptType.8ee
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @At.2(%self.param: %C, %subscript.param: %SubscriptType.8ee) -> %return.param: %ElementType.e6b {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc10_13.1: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %.loc10_13.2: init %ElementType.e6b = class_init (), %return [concrete = constants.%ElementType.val]
+// CHECK:STDOUT:   %.loc10_14: init %ElementType.e6b = converted %.loc10_13.1, %.loc10_13.2 [concrete = constants.%ElementType.val]
+// CHECK:STDOUT:   return %.loc10_14 to %return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc14: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %c.ref: ref %C = name_ref c, file.%c
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
+// CHECK:STDOUT:   %.loc22_25.1: %SubscriptType.8ee = converted %int_0, <error> [concrete = <error>]
+// CHECK:STDOUT:   %impl.elem0: %.d94 = impl_witness_access constants.%IndexWith.impl_witness, element0 [concrete = constants.%At.d43]
+// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %c.ref, %impl.elem0
+// CHECK:STDOUT:   %.loc22_25.2: ref %ElementType.e6b = temporary_storage
+// CHECK:STDOUT:   %.loc22_22: %C = bind_value %c.ref
+// CHECK:STDOUT:   %At.call: init %ElementType.e6b = call %bound_method(%.loc22_22, <error>) to %.loc22_25.2
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: --- fail_index_with_not_implemented.carbon
+// CHECK:STDOUT:
+// CHECK:STDOUT: constants {
+// CHECK:STDOUT:   %C: type = class_type @C [concrete]
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
+// CHECK:STDOUT:   %complete_type.357: <witness> = complete_type_witness %empty_struct_type [concrete]
+// CHECK:STDOUT:   %pattern_type.c48: type = pattern_type %C [concrete]
+// CHECK:STDOUT:   %C.val: %C = struct_value () [concrete]
+// CHECK:STDOUT:   %int_32: Core.IntLiteral = int_value 32 [concrete]
+// CHECK:STDOUT:   %Int.type: type = generic_class_type @Int [concrete]
+// CHECK:STDOUT:   %Int.generic: %Int.type = struct_value () [concrete]
+// CHECK:STDOUT:   %i32: type = class_type @Int, @Int(%int_32) [concrete]
+// CHECK:STDOUT:   %pattern_type.7ce: type = pattern_type %i32 [concrete]
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
+// CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
+// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: imports {
+// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
+// CHECK:STDOUT:     .Int = %Core.Int
+// CHECK:STDOUT:     .IndexWith = %Core.IndexWith
+// CHECK:STDOUT:     import Core//prelude
+// CHECK:STDOUT:     import Core//prelude/...
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.Int: %Int.type = import_ref Core//prelude/types/int, Int, loaded [concrete = constants.%Int.generic]
+// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//prelude/operators/index, IndexWith, loaded [concrete = constants.%IndexWith.generic]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: file {
+// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
+// CHECK:STDOUT:     .Core = imports.%Core
+// CHECK:STDOUT:     .C = %C.decl
+// CHECK:STDOUT:     .c = %c
+// CHECK:STDOUT:     .x = %x
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %Core.import = import Core
+// CHECK:STDOUT:   %C.decl: type = class_decl @C [concrete = constants.%C] {} {}
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %c.patt: %pattern_type.c48 = binding_pattern c [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %C.ref: type = name_ref C, %C.decl [concrete = constants.%C]
+// CHECK:STDOUT:   %.loc6_13.1: ref %C = temporary_storage
+// CHECK:STDOUT:   %.loc6_13.2: init %C = class_init (), %.loc6_13.1 [concrete = constants.%C.val]
+// CHECK:STDOUT:   %.loc6_13.3: ref %C = temporary %.loc6_13.1, %.loc6_13.2
+// CHECK:STDOUT:   %.loc6_13.4: ref %C = converted @__global_init.%.loc6, %.loc6_13.3
+// CHECK:STDOUT:   %c: ref %C = bind_name c, %.loc6_13.4
+// CHECK:STDOUT:   name_binding_decl {
+// CHECK:STDOUT:     %x.patt: %pattern_type.7ce = binding_pattern x [concrete]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %.loc11: type = splice_block %i32 [concrete = constants.%i32] {
+// CHECK:STDOUT:     %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
+// CHECK:STDOUT:     %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
+// CHECK:STDOUT:   }
+// CHECK:STDOUT:   %x: %i32 = bind_name x, <error> [concrete = <error>]
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: class @C {
+// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
+// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type.357]
+// CHECK:STDOUT:   complete_type_witness = %complete_type
+// CHECK:STDOUT:
+// CHECK:STDOUT: !members:
+// CHECK:STDOUT:   .Self = constants.%C
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: fn @__global_init() {
+// CHECK:STDOUT: !entry:
+// CHECK:STDOUT:   %.loc6: %empty_struct_type = struct_literal ()
+// CHECK:STDOUT:   %c.ref: ref %C = name_ref c, file.%c
+// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
+// CHECK:STDOUT:   return
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon b/toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon
deleted file mode 100644
index 990250c5eb2a..000000000000
--- a/toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon
+++ /dev/null
@@ -1,447 +0,0 @@
-// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
-// Exceptions. See /LICENSE for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-// TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
-//
-// AUTOUPDATE
-// TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon
-// TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/operators/overloaded/no_prelude/index.carbon
-
-// --- core_wrong_index_with.carbon
-
-package Core library "[[@TEST_NAME]]";
-
-class IndexWith {}
-
-// --- fail_wrong_index_with.carbon
-
-library "[[@TEST_NAME]]";
-
-import Core library "core_wrong_index_with";
-
-// CHECK:STDERR: fail_wrong_index_with.carbon:[[@LINE+4]]:10: error: type `Core.IntLiteral` does not support indexing [TypeNotIndexable]
-// CHECK:STDERR: fn F() { 0[1]; }
-// CHECK:STDERR:          ^~~~
-// CHECK:STDERR:
-fn F() { 0[1]; }
-
-// --- fail_missing_index_with.carbon
-
-library "[[@TEST_NAME]]";
-
-// CHECK:STDERR: fail_missing_index_with.carbon:[[@LINE+8]]:10: error: `Core.IndexWith` implicitly referenced here, but package `Core` not found [CoreNotFound]
-// CHECK:STDERR: fn F() { 0[1]; }
-// CHECK:STDERR:          ^~~~
-// CHECK:STDERR:
-// CHECK:STDERR: fail_missing_index_with.carbon:[[@LINE+4]]:10: error: type `Core.IntLiteral` does not support indexing [TypeNotIndexable]
-// CHECK:STDERR: fn F() { 0[1]; }
-// CHECK:STDERR:          ^~~~
-// CHECK:STDERR:
-fn F() { 0[1]; }
-
-// --- core_wrong_arg_count.carbon
-
-package Core library "[[@TEST_NAME]]";
-
-interface IndexWith(SubscriptType:! type) {
-  fn At[self: Self](subscript: SubscriptType) -> ();
-}
-
-// --- wrong_arg_count.carbon
-
-library "[[@TEST_NAME]]";
-
-import Core library "core_wrong_arg_count";
-
-impl () as Core.IndexWith(()) {
-  fn At[self: Self](subscript: ()) -> () {
-    return ();
-  }
-}
-
-fn F() { ()[()]; }
-
-// CHECK:STDOUT: --- core_wrong_index_with.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %IndexWith: type = class_type @IndexWith [concrete]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .IndexWith = %IndexWith.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %IndexWith.decl: type = class_decl @IndexWith [concrete = constants.%IndexWith] {} {}
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: class @IndexWith {
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete = constants.%empty_struct_type]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete = constants.%complete_type]
-// CHECK:STDOUT:   complete_type_witness = %complete_type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = constants.%IndexWith
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_wrong_index_with.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %F.type: type = fn_type @F [concrete]
-// CHECK:STDOUT:   %F: %F.type = struct_value () [concrete]
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
-// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete]
-// CHECK:STDOUT:   %IndexWith: type = class_type @IndexWith [concrete]
-// CHECK:STDOUT:   %empty_struct_type: type = struct_type {} [concrete]
-// CHECK:STDOUT:   %complete_type: <witness> = complete_type_witness %empty_struct_type [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
-// CHECK:STDOUT:     .IndexWith = %Core.IndexWith
-// CHECK:STDOUT:     import Core//core_wrong_index_with
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.IndexWith: type = import_ref Core//core_wrong_index_with, IndexWith, loaded [concrete = constants.%IndexWith]
-// CHECK:STDOUT:   %Core.import_ref.8f2: <witness> = import_ref Core//core_wrong_index_with, loc4_18, loaded [concrete = constants.%complete_type]
-// CHECK:STDOUT:   %Core.import_ref.4c7 = import_ref Core//core_wrong_index_with, inst16 [no loc], unloaded
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .Core = imports.%Core
-// CHECK:STDOUT:     .F = %F.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.import = import Core
-// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [concrete = constants.%F] {} {}
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: class @IndexWith [from "core_wrong_index_with.carbon"] {
-// CHECK:STDOUT:   complete_type_witness = imports.%Core.import_ref.8f2
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .Self = imports.%Core.import_ref.4c7
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @F() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
-// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1]
-// CHECK:STDOUT:   return
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- fail_missing_index_with.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %F.type: type = fn_type @F [concrete]
-// CHECK:STDOUT:   %F: %F.type = struct_value () [concrete]
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete]
-// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .F = %F.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [concrete = constants.%F] {} {}
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @F() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %int_0: Core.IntLiteral = int_value 0 [concrete = constants.%int_0]
-// CHECK:STDOUT:   %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1]
-// CHECK:STDOUT:   return
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- core_wrong_arg_count.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic]
-// CHECK:STDOUT:   %pattern_type.98f: type = pattern_type type [concrete]
-// CHECK:STDOUT:   %IndexWith.type.68b: type = generic_interface_type @IndexWith [concrete]
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.68b = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.type.b94: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic]
-// CHECK:STDOUT:   %Self: %IndexWith.type.b94 = bind_symbolic_name Self, 1 [symbolic]
-// CHECK:STDOUT:   %Self.as_type: type = facet_access_type %Self [symbolic]
-// CHECK:STDOUT:   %pattern_type.2ad: type = pattern_type %Self.as_type [symbolic]
-// CHECK:STDOUT:   %pattern_type.7dc: type = pattern_type %SubscriptType [symbolic]
-// CHECK:STDOUT:   %pattern_type.cb1: type = pattern_type %empty_tuple.type [concrete]
-// CHECK:STDOUT:   %At.type: type = fn_type @At, @IndexWith(%SubscriptType) [symbolic]
-// CHECK:STDOUT:   %At: %At.type = struct_value () [symbolic]
-// CHECK:STDOUT:   %IndexWith.assoc_type: type = assoc_entity_type @IndexWith, @IndexWith(%SubscriptType) [symbolic]
-// CHECK:STDOUT:   %assoc0: %IndexWith.assoc_type = assoc_entity element0, @IndexWith.%At.decl [symbolic]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .IndexWith = %IndexWith.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %IndexWith.decl: %IndexWith.type.68b = interface_decl @IndexWith [concrete = constants.%IndexWith.generic] {
-// CHECK:STDOUT:     %SubscriptType.patt: %pattern_type.98f = symbolic_binding_pattern SubscriptType, 0 [concrete]
-// CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %SubscriptType.loc4_21.1: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType.loc4_21.2 (constants.%SubscriptType)]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic interface @IndexWith(%SubscriptType.loc4_21.1: type) {
-// CHECK:STDOUT:   %SubscriptType.loc4_21.2: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType.loc4_21.2 (constants.%SubscriptType)]
-// CHECK:STDOUT:
-// CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(%SubscriptType.loc4_21.2)> [symbolic = %IndexWith.type (constants.%IndexWith.type.b94)]
-// CHECK:STDOUT:   %Self.2: @IndexWith.%IndexWith.type (%IndexWith.type.b94) = bind_symbolic_name Self, 1 [symbolic = %Self.2 (constants.%Self)]
-// CHECK:STDOUT:   %At.type: type = fn_type @At, @IndexWith(%SubscriptType.loc4_21.2) [symbolic = %At.type (constants.%At.type)]
-// CHECK:STDOUT:   %At: @IndexWith.%At.type (%At.type) = struct_value () [symbolic = %At (constants.%At)]
-// CHECK:STDOUT:   %IndexWith.assoc_type: type = assoc_entity_type @IndexWith, @IndexWith(%SubscriptType.loc4_21.2) [symbolic = %IndexWith.assoc_type (constants.%IndexWith.assoc_type)]
-// CHECK:STDOUT:   %assoc0.loc5_52.2: @IndexWith.%IndexWith.assoc_type (%IndexWith.assoc_type) = assoc_entity element0, %At.decl [symbolic = %assoc0.loc5_52.2 (constants.%assoc0)]
-// CHECK:STDOUT:
-// CHECK:STDOUT:   interface {
-// CHECK:STDOUT:     %Self.1: @IndexWith.%IndexWith.type (%IndexWith.type.b94) = bind_symbolic_name Self, 1 [symbolic = %Self.2 (constants.%Self)]
-// CHECK:STDOUT:     %At.decl: @IndexWith.%At.type (%At.type) = fn_decl @At [symbolic = @IndexWith.%At (constants.%At)] {
-// CHECK:STDOUT:       %self.patt: @At.%pattern_type.loc5_9 (%pattern_type.2ad) = binding_pattern self [concrete]
-// CHECK:STDOUT:       %self.param_patt: @At.%pattern_type.loc5_9 (%pattern_type.2ad) = value_param_pattern %self.patt, call_param0 [concrete]
-// CHECK:STDOUT:       %subscript.patt: @At.%pattern_type.loc5_21 (%pattern_type.7dc) = binding_pattern subscript [concrete]
-// CHECK:STDOUT:       %subscript.param_patt: @At.%pattern_type.loc5_21 (%pattern_type.7dc) = value_param_pattern %subscript.patt, call_param1 [concrete]
-// CHECK:STDOUT:       %return.patt: %pattern_type.cb1 = return_slot_pattern [concrete]
-// CHECK:STDOUT:       %return.param_patt: %pattern_type.cb1 = out_param_pattern %return.patt, call_param2 [concrete]
-// CHECK:STDOUT:     } {
-// CHECK:STDOUT:       %.loc5_51.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:       %.loc5_51.2: type = converted %.loc5_51.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:       %self.param: @At.%Self.as_type.loc5_15.1 (%Self.as_type) = value_param call_param0
-// CHECK:STDOUT:       %.loc5_15.1: type = splice_block %.loc5_15.3 [symbolic = %Self.as_type.loc5_15.1 (constants.%Self.as_type)] {
-// CHECK:STDOUT:         %.loc5_15.2: @At.%IndexWith.type (%IndexWith.type.b94) = specific_constant @IndexWith.%Self.1, @IndexWith(constants.%SubscriptType) [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:         %Self.ref: @At.%IndexWith.type (%IndexWith.type.b94) = name_ref Self, %.loc5_15.2 [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:         %Self.as_type.loc5_15.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc5_15.1 (constants.%Self.as_type)]
-// CHECK:STDOUT:         %.loc5_15.3: type = converted %Self.ref, %Self.as_type.loc5_15.2 [symbolic = %Self.as_type.loc5_15.1 (constants.%Self.as_type)]
-// CHECK:STDOUT:       }
-// CHECK:STDOUT:       %self: @At.%Self.as_type.loc5_15.1 (%Self.as_type) = bind_name self, %self.param
-// CHECK:STDOUT:       %subscript.param: @At.%SubscriptType (%SubscriptType) = value_param call_param1
-// CHECK:STDOUT:       %SubscriptType.ref: type = name_ref SubscriptType, @IndexWith.%SubscriptType.loc4_21.1 [symbolic = %SubscriptType (constants.%SubscriptType)]
-// CHECK:STDOUT:       %subscript: @At.%SubscriptType (%SubscriptType) = bind_name subscript, %subscript.param
-// CHECK:STDOUT:       %return.param: ref %empty_tuple.type = out_param call_param2
-// CHECK:STDOUT:       %return: ref %empty_tuple.type = return_slot %return.param
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:     %assoc0.loc5_52.1: @IndexWith.%IndexWith.assoc_type (%IndexWith.assoc_type) = assoc_entity element0, %At.decl [symbolic = %assoc0.loc5_52.2 (constants.%assoc0)]
-// CHECK:STDOUT:
-// CHECK:STDOUT:   !members:
-// CHECK:STDOUT:     .Self = %Self.1
-// CHECK:STDOUT:     .SubscriptType = <poisoned>
-// CHECK:STDOUT:     .At = %assoc0.loc5_52.1
-// CHECK:STDOUT:     witness = (%At.decl)
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @At(@IndexWith.%SubscriptType.loc4_21.1: type, @IndexWith.%Self.1: @IndexWith.%IndexWith.type (%IndexWith.type.b94)) {
-// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType (constants.%SubscriptType)]
-// CHECK:STDOUT:   %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic = %IndexWith.type (constants.%IndexWith.type.b94)]
-// CHECK:STDOUT:   %Self: @At.%IndexWith.type (%IndexWith.type.b94) = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self)]
-// CHECK:STDOUT:   %Self.as_type.loc5_15.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc5_15.1 (constants.%Self.as_type)]
-// CHECK:STDOUT:   %pattern_type.loc5_9: type = pattern_type %Self.as_type.loc5_15.1 [symbolic = %pattern_type.loc5_9 (constants.%pattern_type.2ad)]
-// CHECK:STDOUT:   %pattern_type.loc5_21: type = pattern_type %SubscriptType [symbolic = %pattern_type.loc5_21 (constants.%pattern_type.7dc)]
-// CHECK:STDOUT:
-// CHECK:STDOUT:   fn(%self.param: @At.%Self.as_type.loc5_15.1 (%Self.as_type), %subscript.param: @At.%SubscriptType (%SubscriptType)) -> %empty_tuple.type;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @IndexWith(constants.%SubscriptType) {
-// CHECK:STDOUT:   %SubscriptType.loc4_21.2 => constants.%SubscriptType
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @At(constants.%SubscriptType, constants.%Self) {
-// CHECK:STDOUT:   %SubscriptType => constants.%SubscriptType
-// CHECK:STDOUT:   %IndexWith.type => constants.%IndexWith.type.b94
-// CHECK:STDOUT:   %Self => constants.%Self
-// CHECK:STDOUT:   %Self.as_type.loc5_15.1 => constants.%Self.as_type
-// CHECK:STDOUT:   %pattern_type.loc5_9 => constants.%pattern_type.2ad
-// CHECK:STDOUT:   %pattern_type.loc5_21 => constants.%pattern_type.7dc
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: --- wrong_arg_count.carbon
-// CHECK:STDOUT:
-// CHECK:STDOUT: constants {
-// CHECK:STDOUT:   %empty_tuple.type: type = tuple_type () [concrete]
-// CHECK:STDOUT:   %IndexWith.type.504: type = generic_interface_type @IndexWith [concrete]
-// CHECK:STDOUT:   %IndexWith.generic: %IndexWith.type.504 = struct_value () [concrete]
-// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic]
-// CHECK:STDOUT:   %IndexWith.type.bd2: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic]
-// CHECK:STDOUT:   %Self.30a: %IndexWith.type.bd2 = bind_symbolic_name Self, 1 [symbolic]
-// CHECK:STDOUT:   %At.type.cf4: type = fn_type @At.1, @IndexWith(%SubscriptType) [symbolic]
-// CHECK:STDOUT:   %At.281: %At.type.cf4 = struct_value () [symbolic]
-// CHECK:STDOUT:   %pattern_type.cb1: type = pattern_type %empty_tuple.type [concrete]
-// CHECK:STDOUT:   %Self.as_type: type = facet_access_type %Self.30a [symbolic]
-// CHECK:STDOUT:   %pattern_type.e1a: type = pattern_type %Self.as_type [symbolic]
-// CHECK:STDOUT:   %pattern_type.7dc: type = pattern_type %SubscriptType [symbolic]
-// CHECK:STDOUT:   %IndexWith.assoc_type.290: type = assoc_entity_type @IndexWith, @IndexWith(%SubscriptType) [symbolic]
-// CHECK:STDOUT:   %assoc0.af8: %IndexWith.assoc_type.290 = assoc_entity element0, imports.%Core.import_ref.e99 [symbolic]
-// CHECK:STDOUT:   %IndexWith.type.a51: type = facet_type <@IndexWith, @IndexWith(%empty_tuple.type)> [concrete]
-// CHECK:STDOUT:   %Self.8f0: %IndexWith.type.a51 = bind_symbolic_name Self, 1 [symbolic]
-// CHECK:STDOUT:   %At.type.969: type = fn_type @At.1, @IndexWith(%empty_tuple.type) [concrete]
-// CHECK:STDOUT:   %At.9b9: %At.type.969 = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.assoc_type.3d4: type = assoc_entity_type @IndexWith, @IndexWith(%empty_tuple.type) [concrete]
-// CHECK:STDOUT:   %assoc0.21b: %IndexWith.assoc_type.3d4 = assoc_entity element0, imports.%Core.import_ref.e99 [concrete]
-// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness file.%IndexWith.impl_witness_table [concrete]
-// CHECK:STDOUT:   %At.type.486: type = fn_type @At.2 [concrete]
-// CHECK:STDOUT:   %At.7c4: %At.type.486 = struct_value () [concrete]
-// CHECK:STDOUT:   %IndexWith.facet: %IndexWith.type.a51 = facet_value %empty_tuple.type, (%IndexWith.impl_witness) [concrete]
-// CHECK:STDOUT:   %empty_tuple: %empty_tuple.type = tuple_value () [concrete]
-// CHECK:STDOUT:   %F.type: type = fn_type @F [concrete]
-// CHECK:STDOUT:   %F: %F.type = struct_value () [concrete]
-// CHECK:STDOUT:   %assoc0.e1e: %IndexWith.assoc_type.290 = assoc_entity element0, imports.%Core.import_ref.981 [symbolic]
-// CHECK:STDOUT:   %.ffc: type = fn_type_with_self_type %At.type.969, %IndexWith.facet [concrete]
-// CHECK:STDOUT:   %At.bound: <bound method> = bound_method %empty_tuple, %At.7c4 [concrete]
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: imports {
-// CHECK:STDOUT:   %Core: <namespace> = namespace file.%Core.import, [concrete] {
-// CHECK:STDOUT:     .IndexWith = %Core.IndexWith
-// CHECK:STDOUT:     import Core//core_wrong_arg_count
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.IndexWith: %IndexWith.type.504 = import_ref Core//core_wrong_arg_count, IndexWith, loaded [concrete = constants.%IndexWith.generic]
-// CHECK:STDOUT:   %Core.import_ref.5ab3ec.1: type = import_ref Core//core_wrong_arg_count, loc4_21, loaded [symbolic = @IndexWith.%SubscriptType (constants.%SubscriptType)]
-// CHECK:STDOUT:   %Core.import_ref.68a = import_ref Core//core_wrong_arg_count, inst25 [no loc], unloaded
-// CHECK:STDOUT:   %Core.import_ref.613: @IndexWith.%IndexWith.assoc_type (%IndexWith.assoc_type.290) = import_ref Core//core_wrong_arg_count, loc5_52, loaded [symbolic = @IndexWith.%assoc0 (constants.%assoc0.e1e)]
-// CHECK:STDOUT:   %Core.At: @IndexWith.%At.type (%At.type.cf4) = import_ref Core//core_wrong_arg_count, At, loaded [symbolic = @IndexWith.%At (constants.%At.281)]
-// CHECK:STDOUT:   %Core.import_ref.5ab3ec.2: type = import_ref Core//core_wrong_arg_count, loc4_21, loaded [symbolic = @IndexWith.%SubscriptType (constants.%SubscriptType)]
-// CHECK:STDOUT:   %Core.import_ref.fb5: @IndexWith.%IndexWith.type (%IndexWith.type.bd2) = import_ref Core//core_wrong_arg_count, inst25 [no loc], loaded [symbolic = @IndexWith.%Self (constants.%Self.30a)]
-// CHECK:STDOUT:   %Core.import_ref.e99: @IndexWith.%At.type (%At.type.cf4) = import_ref Core//core_wrong_arg_count, loc5_52, loaded [symbolic = @IndexWith.%At (constants.%At.281)]
-// CHECK:STDOUT:   %Core.import_ref.981 = import_ref Core//core_wrong_arg_count, loc5_52, unloaded
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: file {
-// CHECK:STDOUT:   package: <namespace> = namespace [concrete] {
-// CHECK:STDOUT:     .Core = imports.%Core
-// CHECK:STDOUT:     .F = %F.decl
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %Core.import = import Core
-// CHECK:STDOUT:   impl_decl @impl [concrete] {} {
-// CHECK:STDOUT:     %.loc6_7.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc6_7.2: type = converted %.loc6_7.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %Core.ref: <namespace> = name_ref Core, imports.%Core [concrete = imports.%Core]
-// CHECK:STDOUT:     %IndexWith.ref: %IndexWith.type.504 = name_ref IndexWith, imports.%Core.IndexWith [concrete = constants.%IndexWith.generic]
-// CHECK:STDOUT:     %.loc6_28: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc6_29: type = converted %.loc6_28, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(constants.%empty_tuple.type)> [concrete = constants.%IndexWith.type.a51]
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:   %IndexWith.impl_witness_table = impl_witness_table (@impl.%At.decl), @impl [concrete]
-// CHECK:STDOUT:   %IndexWith.impl_witness: <witness> = impl_witness %IndexWith.impl_witness_table [concrete = constants.%IndexWith.impl_witness]
-// CHECK:STDOUT:   %F.decl: %F.type = fn_decl @F [concrete = constants.%F] {} {}
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic interface @IndexWith(imports.%Core.import_ref.5ab3ec.1: type) [from "core_wrong_arg_count.carbon"] {
-// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType (constants.%SubscriptType)]
-// CHECK:STDOUT:
-// CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic = %IndexWith.type (constants.%IndexWith.type.bd2)]
-// CHECK:STDOUT:   %Self: @IndexWith.%IndexWith.type (%IndexWith.type.bd2) = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self.30a)]
-// CHECK:STDOUT:   %At.type: type = fn_type @At.1, @IndexWith(%SubscriptType) [symbolic = %At.type (constants.%At.type.cf4)]
-// CHECK:STDOUT:   %At: @IndexWith.%At.type (%At.type.cf4) = struct_value () [symbolic = %At (constants.%At.281)]
-// CHECK:STDOUT:   %IndexWith.assoc_type: type = assoc_entity_type @IndexWith, @IndexWith(%SubscriptType) [symbolic = %IndexWith.assoc_type (constants.%IndexWith.assoc_type.290)]
-// CHECK:STDOUT:   %assoc0: @IndexWith.%IndexWith.assoc_type (%IndexWith.assoc_type.290) = assoc_entity element0, imports.%Core.import_ref.e99 [symbolic = %assoc0 (constants.%assoc0.af8)]
-// CHECK:STDOUT:
-// CHECK:STDOUT:   interface {
-// CHECK:STDOUT:   !members:
-// CHECK:STDOUT:     .Self = imports.%Core.import_ref.68a
-// CHECK:STDOUT:     .At = imports.%Core.import_ref.613
-// CHECK:STDOUT:     witness = (imports.%Core.At)
-// CHECK:STDOUT:   }
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: impl @impl: %.loc6_7.2 as %IndexWith.type {
-// CHECK:STDOUT:   %At.decl: %At.type.486 = fn_decl @At.2 [concrete = constants.%At.7c4] {
-// CHECK:STDOUT:     %self.patt: %pattern_type.cb1 = binding_pattern self [concrete]
-// CHECK:STDOUT:     %self.param_patt: %pattern_type.cb1 = value_param_pattern %self.patt, call_param0 [concrete]
-// CHECK:STDOUT:     %subscript.patt: %pattern_type.cb1 = binding_pattern subscript [concrete]
-// CHECK:STDOUT:     %subscript.param_patt: %pattern_type.cb1 = value_param_pattern %subscript.patt, call_param1 [concrete]
-// CHECK:STDOUT:     %return.patt: %pattern_type.cb1 = return_slot_pattern [concrete]
-// CHECK:STDOUT:     %return.param_patt: %pattern_type.cb1 = out_param_pattern %return.patt, call_param2 [concrete]
-// CHECK:STDOUT:   } {
-// CHECK:STDOUT:     %.loc7_40.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:     %.loc7_40.2: type = converted %.loc7_40.1, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %self.param: %empty_tuple.type = value_param call_param0
-// CHECK:STDOUT:     %Self.ref: type = name_ref Self, @impl.%.loc6_7.2 [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     %self: %empty_tuple.type = bind_name self, %self.param
-// CHECK:STDOUT:     %subscript.param: %empty_tuple.type = value_param call_param1
-// CHECK:STDOUT:     %.loc7_33.1: type = splice_block %.loc7_33.3 [concrete = constants.%empty_tuple.type] {
-// CHECK:STDOUT:       %.loc7_33.2: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:       %.loc7_33.3: type = converted %.loc7_33.2, constants.%empty_tuple.type [concrete = constants.%empty_tuple.type]
-// CHECK:STDOUT:     }
-// CHECK:STDOUT:     %subscript: %empty_tuple.type = bind_name subscript, %subscript.param
-// CHECK:STDOUT:     %return.param: ref %empty_tuple.type = out_param call_param2
-// CHECK:STDOUT:     %return: ref %empty_tuple.type = return_slot %return.param
-// CHECK:STDOUT:   }
-// CHECK:STDOUT:
-// CHECK:STDOUT: !members:
-// CHECK:STDOUT:   .At = %At.decl
-// CHECK:STDOUT:   witness = file.%IndexWith.impl_witness
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: generic fn @At.1(imports.%Core.import_ref.5ab3ec.2: type, imports.%Core.import_ref.fb5: @IndexWith.%IndexWith.type (%IndexWith.type.bd2)) [from "core_wrong_arg_count.carbon"] {
-// CHECK:STDOUT:   %SubscriptType: type = bind_symbolic_name SubscriptType, 0 [symbolic = %SubscriptType (constants.%SubscriptType)]
-// CHECK:STDOUT:   %IndexWith.type: type = facet_type <@IndexWith, @IndexWith(%SubscriptType)> [symbolic = %IndexWith.type (constants.%IndexWith.type.bd2)]
-// CHECK:STDOUT:   %Self: @At.1.%IndexWith.type (%IndexWith.type.bd2) = bind_symbolic_name Self, 1 [symbolic = %Self (constants.%Self.30a)]
-// CHECK:STDOUT:   %Self.as_type: type = facet_access_type %Self [symbolic = %Self.as_type (constants.%Self.as_type)]
-// CHECK:STDOUT:   %pattern_type.1: type = pattern_type %Self.as_type [symbolic = %pattern_type.1 (constants.%pattern_type.e1a)]
-// CHECK:STDOUT:   %pattern_type.2: type = pattern_type %SubscriptType [symbolic = %pattern_type.2 (constants.%pattern_type.7dc)]
-// CHECK:STDOUT:
-// CHECK:STDOUT:   fn;
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @At.2(%self.param: %empty_tuple.type, %subscript.param: %empty_tuple.type) -> %empty_tuple.type {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc8_13: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %empty_tuple: %empty_tuple.type = tuple_value () [concrete = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc8_14: %empty_tuple.type = converted %.loc8_13, %empty_tuple [concrete = constants.%empty_tuple]
-// CHECK:STDOUT:   return %.loc8_14
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: fn @F() {
-// CHECK:STDOUT: !entry:
-// CHECK:STDOUT:   %.loc12_11.1: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %.loc12_14: %empty_tuple.type = tuple_literal ()
-// CHECK:STDOUT:   %empty_tuple.loc12_11: %empty_tuple.type = tuple_value () [concrete = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc12_11.2: %empty_tuple.type = converted %.loc12_11.1, %empty_tuple.loc12_11 [concrete = constants.%empty_tuple]
-// CHECK:STDOUT:   %empty_tuple.loc12_14: %empty_tuple.type = tuple_value () [concrete = constants.%empty_tuple]
-// CHECK:STDOUT:   %.loc12_15: %empty_tuple.type = converted %.loc12_14, %empty_tuple.loc12_14 [concrete = constants.%empty_tuple]
-// CHECK:STDOUT:   %impl.elem0: %.ffc = impl_witness_access constants.%IndexWith.impl_witness, element0 [concrete = constants.%At.7c4]
-// CHECK:STDOUT:   %bound_method: <bound method> = bound_method %.loc12_11.2, %impl.elem0 [concrete = constants.%At.bound]
-// CHECK:STDOUT:   %At.call: init %empty_tuple.type = call %bound_method(%.loc12_11.2, %.loc12_15)
-// CHECK:STDOUT:   return
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @IndexWith(constants.%SubscriptType) {
-// CHECK:STDOUT:   %SubscriptType => constants.%SubscriptType
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @At.1(constants.%SubscriptType, constants.%Self.30a) {
-// CHECK:STDOUT:   %SubscriptType => constants.%SubscriptType
-// CHECK:STDOUT:   %IndexWith.type => constants.%IndexWith.type.bd2
-// CHECK:STDOUT:   %Self => constants.%Self.30a
-// CHECK:STDOUT:   %Self.as_type => constants.%Self.as_type
-// CHECK:STDOUT:   %pattern_type.1 => constants.%pattern_type.e1a
-// CHECK:STDOUT:   %pattern_type.2 => constants.%pattern_type.7dc
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @IndexWith(constants.%empty_tuple.type) {
-// CHECK:STDOUT:   %SubscriptType => constants.%empty_tuple.type
-// CHECK:STDOUT:
-// CHECK:STDOUT: !definition:
-// CHECK:STDOUT:   %IndexWith.type => constants.%IndexWith.type.a51
-// CHECK:STDOUT:   %Self => constants.%Self.8f0
-// CHECK:STDOUT:   %At.type => constants.%At.type.969
-// CHECK:STDOUT:   %At => constants.%At.9b9
-// CHECK:STDOUT:   %IndexWith.assoc_type => constants.%IndexWith.assoc_type.3d4
-// CHECK:STDOUT:   %assoc0 => constants.%assoc0.21b
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
-// CHECK:STDOUT: specific @At.1(constants.%empty_tuple.type, constants.%IndexWith.facet) {
-// CHECK:STDOUT:   %SubscriptType => constants.%empty_tuple.type
-// CHECK:STDOUT:   %IndexWith.type => constants.%IndexWith.type.a51
-// CHECK:STDOUT:   %Self => constants.%IndexWith.facet
-// CHECK:STDOUT:   %Self.as_type => constants.%empty_tuple.type
-// CHECK:STDOUT:   %pattern_type.1 => constants.%pattern_type.cb1
-// CHECK:STDOUT:   %pattern_type.2 => constants.%pattern_type.cb1
-// CHECK:STDOUT: }
-// CHECK:STDOUT:
diff --git a/toolchain/check/testdata/packages/no_prelude/core_name_poisoning.carbon b/toolchain/check/testdata/packages/core_name_poisoning.carbon
similarity index 79%
rename from toolchain/check/testdata/packages/no_prelude/core_name_poisoning.carbon
rename to toolchain/check/testdata/packages/core_name_poisoning.carbon
index c27a06589f8f..1c7b3e9264b0 100644
--- a/toolchain/check/testdata/packages/no_prelude/core_name_poisoning.carbon
+++ b/toolchain/check/testdata/packages/core_name_poisoning.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/core_name_poisoning.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/core_name_poisoning.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/core_name_poisoning.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/core_name_poisoning.carbon
 
 // --- fail_implicitly_poison_core.carbon
 
diff --git a/toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon b/toolchain/check/testdata/packages/cross_package_export.carbon
similarity index 99%
rename from toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon
rename to toolchain/check/testdata/packages/cross_package_export.carbon
index 821ad3246736..c20b60f40dd3 100644
--- a/toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon
+++ b/toolchain/check/testdata/packages/cross_package_export.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/cross_package_export.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/cross_package_export.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/cross_package_export.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon b/toolchain/check/testdata/packages/cross_package_import.carbon
similarity index 99%
rename from toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon
rename to toolchain/check/testdata/packages/cross_package_import.carbon
index e9611ba52842..05e41ce85c1a 100644
--- a/toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon
+++ b/toolchain/check/testdata/packages/cross_package_import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/cross_package_import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/cross_package_import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/cross_package_import.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/packages/no_prelude/export_import.carbon b/toolchain/check/testdata/packages/export_import.carbon
similarity index 99%
rename from toolchain/check/testdata/packages/no_prelude/export_import.carbon
rename to toolchain/check/testdata/packages/export_import.carbon
index cb9a42648363..aba32de617f4 100644
--- a/toolchain/check/testdata/packages/no_prelude/export_import.carbon
+++ b/toolchain/check/testdata/packages/export_import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/export_import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/export_import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/export_import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/export_import.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/packages/no_prelude/export_mixed.carbon b/toolchain/check/testdata/packages/export_mixed.carbon
similarity index 99%
rename from toolchain/check/testdata/packages/no_prelude/export_mixed.carbon
rename to toolchain/check/testdata/packages/export_mixed.carbon
index 89a44ba7877e..ba9e828337c2 100644
--- a/toolchain/check/testdata/packages/no_prelude/export_mixed.carbon
+++ b/toolchain/check/testdata/packages/export_mixed.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/export_mixed.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/export_mixed.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/export_mixed.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/export_mixed.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/packages/no_prelude/export_name.carbon b/toolchain/check/testdata/packages/export_name.carbon
similarity index 99%
rename from toolchain/check/testdata/packages/no_prelude/export_name.carbon
rename to toolchain/check/testdata/packages/export_name.carbon
index 4b70994f0418..2eac47267050 100644
--- a/toolchain/check/testdata/packages/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/packages/export_name.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/export_name.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/export_name.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/export_name.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/export_name.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon b/toolchain/check/testdata/packages/fail_export_name_member.carbon
similarity index 94%
rename from toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon
rename to toolchain/check/testdata/packages/fail_export_name_member.carbon
index 00c230690571..1a7ee03ffaa9 100644
--- a/toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon
+++ b/toolchain/check/testdata/packages/fail_export_name_member.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/fail_export_name_member.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/fail_export_name_member.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/fail_export_name_member.carbon
 
 // --- a.carbon
 
diff --git a/toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon b/toolchain/check/testdata/packages/fail_export_name_params.carbon
similarity index 95%
rename from toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon
rename to toolchain/check/testdata/packages/fail_export_name_params.carbon
index 7a2000e64c6b..9910426304a1 100644
--- a/toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon
+++ b/toolchain/check/testdata/packages/fail_export_name_params.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/fail_export_name_params.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/fail_export_name_params.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/fail_export_name_params.carbon
 
 // --- a.carbon
 
diff --git a/toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/packages/fail_modifiers.carbon
similarity index 96%
rename from toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon
rename to toolchain/check/testdata/packages/fail_modifiers.carbon
index a1a65cfaf639..ce75c8f5c433 100644
--- a/toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/packages/fail_modifiers.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/fail_modifiers.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/fail_modifiers.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/fail_modifiers.carbon
 
 // --- fail_extend_package.carbon
 
diff --git a/toolchain/check/testdata/packages/no_prelude/implicit_imports_empty.carbon b/toolchain/check/testdata/packages/implicit_imports_empty.carbon
similarity index 93%
rename from toolchain/check/testdata/packages/no_prelude/implicit_imports_empty.carbon
rename to toolchain/check/testdata/packages/implicit_imports_empty.carbon
index eef11f082843..872ab87220ec 100644
--- a/toolchain/check/testdata/packages/no_prelude/implicit_imports_empty.carbon
+++ b/toolchain/check/testdata/packages/implicit_imports_empty.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/implicit_imports_empty.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/implicit_imports_empty.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/implicit_imports_empty.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/implicit_imports_empty.carbon
 
 // --- api_only.carbon
 
diff --git a/toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon b/toolchain/check/testdata/packages/implicit_imports_entities.carbon
similarity index 99%
rename from toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon
rename to toolchain/check/testdata/packages/implicit_imports_entities.carbon
index ffabdce09103..2a5011fe6936 100644
--- a/toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon
+++ b/toolchain/check/testdata/packages/implicit_imports_entities.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/implicit_imports_entities.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/implicit_imports_entities.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/implicit_imports_entities.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon b/toolchain/check/testdata/packages/missing_prelude.carbon
similarity index 98%
rename from toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon
rename to toolchain/check/testdata/packages/missing_prelude.carbon
index 38115d630fa6..58be52c39431 100644
--- a/toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon
+++ b/toolchain/check/testdata/packages/missing_prelude.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/missing_prelude.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/missing_prelude.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/missing_prelude.carbon
 
 // --- fail_missing_prelude.carbon
 
diff --git a/toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon b/toolchain/check/testdata/packages/restricted_package_names.carbon
similarity index 95%
rename from toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon
rename to toolchain/check/testdata/packages/restricted_package_names.carbon
index 6a5c34a0381c..0deef8569ada 100644
--- a/toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon
+++ b/toolchain/check/testdata/packages/restricted_package_names.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/packages/restricted_package_names.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/no_prelude/restricted_package_names.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/packages/restricted_package_names.carbon
 
 // --- lowercase_main.carbon
 
diff --git a/toolchain/check/testdata/struct/no_prelude/empty.carbon b/toolchain/check/testdata/struct/empty.carbon
similarity index 94%
rename from toolchain/check/testdata/struct/no_prelude/empty.carbon
rename to toolchain/check/testdata/struct/empty.carbon
index 07076f385982..f3d4f72250ce 100644
--- a/toolchain/check/testdata/struct/no_prelude/empty.carbon
+++ b/toolchain/check/testdata/struct/empty.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/struct/no_prelude/empty.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/struct/empty.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/no_prelude/empty.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/empty.carbon
 
 var x: {} = {};
 var y: {} = x;
diff --git a/toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon b/toolchain/check/testdata/struct/fail_assign_nested.carbon
similarity index 92%
rename from toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon
rename to toolchain/check/testdata/struct/fail_assign_nested.carbon
index 8393941656bb..2419bb050e6f 100644
--- a/toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon
+++ b/toolchain/check/testdata/struct/fail_assign_nested.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/struct/fail_assign_nested.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/no_prelude/fail_assign_nested.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_assign_nested.carbon
 
 // CHECK:STDERR: fail_assign_nested.carbon:[[@LINE+4]]:19: error: missing value for field `a` in struct initialization [StructInitMissingFieldInLiteral]
 // CHECK:STDERR: var x: {.a: {}} = {.b = {}};
diff --git a/toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon b/toolchain/check/testdata/struct/fail_nested_incomplete.carbon
similarity index 94%
rename from toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon
rename to toolchain/check/testdata/struct/fail_nested_incomplete.carbon
index 6650572fa2dc..c6eeb4edbf4d 100644
--- a/toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon
+++ b/toolchain/check/testdata/struct/fail_nested_incomplete.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/struct/fail_nested_incomplete.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/no_prelude/fail_nested_incomplete.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/struct/fail_nested_incomplete.carbon
 
 class Incomplete;
 
diff --git a/toolchain/check/testdata/tuple/no_prelude/basics.carbon b/toolchain/check/testdata/tuple/basics.carbon
similarity index 99%
rename from toolchain/check/testdata/tuple/no_prelude/basics.carbon
rename to toolchain/check/testdata/tuple/basics.carbon
index 4a2d7bb6ecc0..00a07d43e75c 100644
--- a/toolchain/check/testdata/tuple/no_prelude/basics.carbon
+++ b/toolchain/check/testdata/tuple/basics.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/tuple/no_prelude/basics.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/tuple/basics.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/no_prelude/basics.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/tuple/basics.carbon
 
 // Because tuples underly a lot of types, try to keep this file to have
 // minimal dependencies on other language syntax (particularly avoiding `class`
diff --git a/toolchain/check/testdata/var/no_prelude/export_name.carbon b/toolchain/check/testdata/var/export_name.carbon
similarity index 96%
rename from toolchain/check/testdata/var/no_prelude/export_name.carbon
rename to toolchain/check/testdata/var/export_name.carbon
index e6faec703a84..958612dbebcb 100644
--- a/toolchain/check/testdata/var/no_prelude/export_name.carbon
+++ b/toolchain/check/testdata/var/export_name.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/export_name.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/export_name.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/export_name.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/export_name.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/check/testdata/var/no_prelude/fail_generic.carbon b/toolchain/check/testdata/var/fail_generic.carbon
similarity index 85%
rename from toolchain/check/testdata/var/no_prelude/fail_generic.carbon
rename to toolchain/check/testdata/var/fail_generic.carbon
index 1a5a88aa1cdf..3bc2d3abe7eb 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_generic.carbon
+++ b/toolchain/check/testdata/var/fail_generic.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/fail_generic.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/fail_generic.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/fail_generic.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/fail_generic.carbon
 
 fn Main() {
   // CHECK:STDERR: fail_generic.carbon:[[@LINE+8]]:7: error: semantics TODO: `handle invalid parse trees in `check`` [SemanticsTodo]
diff --git a/toolchain/check/testdata/var/no_prelude/fail_in_interface.carbon b/toolchain/check/testdata/var/fail_in_interface.carbon
similarity index 91%
rename from toolchain/check/testdata/var/no_prelude/fail_in_interface.carbon
rename to toolchain/check/testdata/var/fail_in_interface.carbon
index a92cda72592d..a0aed8c6ff5a 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_in_interface.carbon
+++ b/toolchain/check/testdata/var/fail_in_interface.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/fail_in_interface.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/fail_in_interface.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/fail_in_interface.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/fail_in_interface.carbon
 
 interface I {
   // CHECK:STDERR: fail_in_interface.carbon:[[@LINE+4]]:11: error: found runtime binding pattern in associated constant declaration; expected a `:!` binding [ExpectedSymbolicBindingInAssociatedConstant]
diff --git a/toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon b/toolchain/check/testdata/var/fail_init_type_mismatch.carbon
similarity index 92%
rename from toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon
rename to toolchain/check/testdata/var/fail_init_type_mismatch.carbon
index ff976fa76bde..443295fb6e90 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon
+++ b/toolchain/check/testdata/var/fail_init_type_mismatch.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/fail_init_type_mismatch.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/fail_init_type_mismatch.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/fail_init_type_mismatch.carbon
 
 // CHECK:STDERR: fail_init_type_mismatch.carbon:[[@LINE+4]]:1: error: `Core.ImplicitAs` implicitly referenced here, but package `Core` not found [CoreNotFound]
 // CHECK:STDERR: var x: {} = ();
diff --git a/toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon b/toolchain/check/testdata/var/fail_modifiers.carbon
similarity index 96%
rename from toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon
rename to toolchain/check/testdata/var/fail_modifiers.carbon
index 1d1cb7fc117b..50e5c2ddbb41 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon
+++ b/toolchain/check/testdata/var/fail_modifiers.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/fail_modifiers.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/fail_modifiers.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/fail_modifiers.carbon
 
 // CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: error: `protected` not allowed; requires class scope [ModifierProtectedNotAllowed]
 // CHECK:STDERR: protected var b: ();
diff --git a/toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon b/toolchain/check/testdata/var/fail_namespace_conflict.carbon
similarity index 94%
rename from toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon
rename to toolchain/check/testdata/var/fail_namespace_conflict.carbon
index e52b73e553de..c187cfc5381e 100644
--- a/toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon
+++ b/toolchain/check/testdata/var/fail_namespace_conflict.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/fail_namespace_conflict.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/fail_namespace_conflict.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/fail_namespace_conflict.carbon
 
 namespace A;
 
diff --git a/toolchain/check/testdata/var/no_prelude/global_decl.carbon b/toolchain/check/testdata/var/global_decl.carbon
similarity index 90%
rename from toolchain/check/testdata/var/no_prelude/global_decl.carbon
rename to toolchain/check/testdata/var/global_decl.carbon
index 07bb542f4e88..9fce292ccf3f 100644
--- a/toolchain/check/testdata/var/no_prelude/global_decl.carbon
+++ b/toolchain/check/testdata/var/global_decl.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/global_decl.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/global_decl.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/global_decl.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/global_decl.carbon
 
 var x: {.v: ()};
 
diff --git a/toolchain/check/testdata/var/no_prelude/global_decl_import.carbon b/toolchain/check/testdata/var/global_decl_import.carbon
similarity index 96%
rename from toolchain/check/testdata/var/no_prelude/global_decl_import.carbon
rename to toolchain/check/testdata/var/global_decl_import.carbon
index 695e8dc7b61e..b3606b06f4e6 100644
--- a/toolchain/check/testdata/var/no_prelude/global_decl_import.carbon
+++ b/toolchain/check/testdata/var/global_decl_import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/global_decl_import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/global_decl_import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/global_decl_import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/global_decl_import.carbon
 
 // --- decl.carbon
 
diff --git a/toolchain/check/testdata/var/no_prelude/global_decl_with_init.carbon b/toolchain/check/testdata/var/global_decl_with_init.carbon
similarity index 97%
rename from toolchain/check/testdata/var/no_prelude/global_decl_with_init.carbon
rename to toolchain/check/testdata/var/global_decl_with_init.carbon
index b374c3e0167d..8935145f43e3 100644
--- a/toolchain/check/testdata/var/no_prelude/global_decl_with_init.carbon
+++ b/toolchain/check/testdata/var/global_decl_with_init.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/global_decl_with_init.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/global_decl_with_init.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/global_decl_with_init.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/global_decl_with_init.carbon
 
 // --- simple.carbon
 
diff --git a/toolchain/check/testdata/var/no_prelude/global_lookup.carbon b/toolchain/check/testdata/var/global_lookup.carbon
similarity index 96%
rename from toolchain/check/testdata/var/no_prelude/global_lookup.carbon
rename to toolchain/check/testdata/var/global_lookup.carbon
index c35b802f030e..92e5b3aef563 100644
--- a/toolchain/check/testdata/var/no_prelude/global_lookup.carbon
+++ b/toolchain/check/testdata/var/global_lookup.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/global_lookup.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/global_lookup.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/global_lookup.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/global_lookup.carbon
 
 var x: {.v: ()} = {.v = ()};
 var y: {.v: ()} = x;
diff --git a/toolchain/check/testdata/var/no_prelude/import.carbon b/toolchain/check/testdata/var/import.carbon
similarity index 96%
rename from toolchain/check/testdata/var/no_prelude/import.carbon
rename to toolchain/check/testdata/var/import.carbon
index 41ca7ba55265..08264012c67c 100644
--- a/toolchain/check/testdata/var/no_prelude/import.carbon
+++ b/toolchain/check/testdata/var/import.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/import.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/import.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/import.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/import.carbon
 
 // --- implicit.carbon
 
diff --git a/toolchain/check/testdata/var/no_prelude/import_access.carbon b/toolchain/check/testdata/var/import_access.carbon
similarity index 97%
rename from toolchain/check/testdata/var/no_prelude/import_access.carbon
rename to toolchain/check/testdata/var/import_access.carbon
index 6a0fcb982148..7107f2c7e3ad 100644
--- a/toolchain/check/testdata/var/no_prelude/import_access.carbon
+++ b/toolchain/check/testdata/var/import_access.carbon
@@ -3,13 +3,13 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 // TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
-// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+// EXTRA-ARGS: --no-prelude-import --dump-sem-ir-ranges=if-present
 //
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/no_prelude/import_access.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/var/import_access.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/no_prelude/import_access.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/var/import_access.carbon
 
 // ============================================================================
 // Setup files
diff --git a/toolchain/lower/testdata/builtins/no_prelude/bool.carbon b/toolchain/lower/testdata/builtins/bool.carbon
similarity index 76%
rename from toolchain/lower/testdata/builtins/no_prelude/bool.carbon
rename to toolchain/lower/testdata/builtins/bool.carbon
index 1b8b158f9464..0694da461468 100644
--- a/toolchain/lower/testdata/builtins/no_prelude/bool.carbon
+++ b/toolchain/lower/testdata/builtins/bool.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/builtins/no_prelude/bool.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/builtins/bool.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/builtins/no_prelude/bool.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/builtins/bool.carbon
 
 fn Bool() -> type = "bool.make_type";
 
@@ -55,16 +57,16 @@ fn IfEq(a: Bool(), b: Bool()) -> Bool() {
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
 // CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "bool.carbon", directory: "")
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestEq", linkageName: "_CTestEq.Main", scope: null, file: !3, line: 14, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestEq", linkageName: "_CTestEq.Main", scope: null, file: !3, line: 16, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{}
-// CHECK:STDOUT: !7 = !DILocation(line: 14, column: 52, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 14, column: 45, scope: !4)
-// CHECK:STDOUT: !9 = distinct !DISubprogram(name: "TestNeq", linkageName: "_CTestNeq.Main", scope: null, file: !3, line: 17, type: !5, spFlags: DISPFlagDefinition, unit: !2)
-// CHECK:STDOUT: !10 = !DILocation(line: 17, column: 53, scope: !9)
-// CHECK:STDOUT: !11 = !DILocation(line: 17, column: 46, scope: !9)
-// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "IfEq", linkageName: "_CIfEq.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
-// CHECK:STDOUT: !13 = !DILocation(line: 20, column: 7, scope: !12)
-// CHECK:STDOUT: !14 = !DILocation(line: 20, column: 6, scope: !12)
-// CHECK:STDOUT: !15 = !DILocation(line: 20, column: 19, scope: !12)
-// CHECK:STDOUT: !16 = !DILocation(line: 21, column: 3, scope: !12)
+// CHECK:STDOUT: !7 = !DILocation(line: 16, column: 52, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 16, column: 45, scope: !4)
+// CHECK:STDOUT: !9 = distinct !DISubprogram(name: "TestNeq", linkageName: "_CTestNeq.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !10 = !DILocation(line: 19, column: 53, scope: !9)
+// CHECK:STDOUT: !11 = !DILocation(line: 19, column: 46, scope: !9)
+// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "IfEq", linkageName: "_CIfEq.Main", scope: null, file: !3, line: 21, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !13 = !DILocation(line: 22, column: 7, scope: !12)
+// CHECK:STDOUT: !14 = !DILocation(line: 22, column: 6, scope: !12)
+// CHECK:STDOUT: !15 = !DILocation(line: 22, column: 19, scope: !12)
+// CHECK:STDOUT: !16 = !DILocation(line: 23, column: 3, scope: !12)
diff --git a/toolchain/lower/testdata/builtins/no_prelude/no_op.carbon b/toolchain/lower/testdata/builtins/no_op.carbon
similarity index 74%
rename from toolchain/lower/testdata/builtins/no_prelude/no_op.carbon
rename to toolchain/lower/testdata/builtins/no_op.carbon
index 2cd61de0c25a..9a674abaf17f 100644
--- a/toolchain/lower/testdata/builtins/no_prelude/no_op.carbon
+++ b/toolchain/lower/testdata/builtins/no_op.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/builtins/no_prelude/no_op.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/builtins/no_op.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/builtins/no_prelude/no_op.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/builtins/no_op.carbon
 
 fn NoOp() = "no_op";
 
@@ -48,7 +50,7 @@ fn J() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: define void @_CH.Main() !dbg !11 {
 // CHECK:STDOUT: entry:
-// CHECK:STDOUT:   %.loc25_18.1.temp = alloca {}, align 8, !dbg !12
+// CHECK:STDOUT:   %.loc27_18.1.temp = alloca {}, align 8, !dbg !12
 // CHECK:STDOUT:   ret void, !dbg !13
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -57,7 +59,7 @@ fn J() {
 // CHECK:STDOUT: define void @_CJ.Main() !dbg !14 {
 // CHECK:STDOUT: entry:
 // CHECK:STDOUT:   call void @_CI.Main(), !dbg !15
-// CHECK:STDOUT:   %.loc31_11.1.temp = alloca {}, align 8, !dbg !15
+// CHECK:STDOUT:   %.loc33_11.1.temp = alloca {}, align 8, !dbg !15
 // CHECK:STDOUT:   ret void, !dbg !16
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
@@ -73,16 +75,16 @@ fn J() {
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
 // CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "no_op.carbon", directory: "")
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 17, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{}
-// CHECK:STDOUT: !7 = !DILocation(line: 15, column: 1, scope: !4)
-// CHECK:STDOUT: !8 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
-// CHECK:STDOUT: !9 = !DILocation(line: 20, column: 3, scope: !8)
-// CHECK:STDOUT: !10 = !DILocation(line: 21, column: 3, scope: !8)
-// CHECK:STDOUT: !11 = distinct !DISubprogram(name: "H", linkageName: "_CH.Main", scope: null, file: !3, line: 24, type: !5, spFlags: DISPFlagDefinition, unit: !2)
-// CHECK:STDOUT: !12 = !DILocation(line: 25, column: 10, scope: !11)
-// CHECK:STDOUT: !13 = !DILocation(line: 25, column: 3, scope: !11)
-// CHECK:STDOUT: !14 = distinct !DISubprogram(name: "J", linkageName: "_CJ.Main", scope: null, file: !3, line: 30, type: !5, spFlags: DISPFlagDefinition, unit: !2)
-// CHECK:STDOUT: !15 = !DILocation(line: 31, column: 9, scope: !14)
-// CHECK:STDOUT: !16 = !DILocation(line: 30, column: 1, scope: !14)
+// CHECK:STDOUT: !7 = !DILocation(line: 17, column: 1, scope: !4)
+// CHECK:STDOUT: !8 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main", scope: null, file: !3, line: 21, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !9 = !DILocation(line: 22, column: 3, scope: !8)
+// CHECK:STDOUT: !10 = !DILocation(line: 23, column: 3, scope: !8)
+// CHECK:STDOUT: !11 = distinct !DISubprogram(name: "H", linkageName: "_CH.Main", scope: null, file: !3, line: 26, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !12 = !DILocation(line: 27, column: 10, scope: !11)
+// CHECK:STDOUT: !13 = !DILocation(line: 27, column: 3, scope: !11)
+// CHECK:STDOUT: !14 = distinct !DISubprogram(name: "J", linkageName: "_CJ.Main", scope: null, file: !3, line: 32, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !15 = !DILocation(line: 33, column: 9, scope: !14)
+// CHECK:STDOUT: !16 = !DILocation(line: 32, column: 1, scope: !14)
diff --git a/toolchain/lower/testdata/builtins/no_prelude/types.carbon b/toolchain/lower/testdata/builtins/types.carbon
similarity index 85%
rename from toolchain/lower/testdata/builtins/no_prelude/types.carbon
rename to toolchain/lower/testdata/builtins/types.carbon
index ce16fa6bfce3..36a40d1a792d 100644
--- a/toolchain/lower/testdata/builtins/no_prelude/types.carbon
+++ b/toolchain/lower/testdata/builtins/types.carbon
@@ -2,11 +2,13 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// EXTRA-ARGS: --no-prelude-import
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
-// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/builtins/no_prelude/types.carbon
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/builtins/types.carbon
 // TIP: To dump output, run:
-// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/builtins/no_prelude/types.carbon
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/builtins/types.carbon
 
 fn IntLiteral() -> type = "int_literal.make_type";
 fn Int(size: IntLiteral()) -> type = "int.make_type_signed";
@@ -52,10 +54,10 @@ fn F() {
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
 // CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "types.carbon", directory: "")
-// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 17, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
 // CHECK:STDOUT: !6 = !{}
-// CHECK:STDOUT: !7 = !DILocation(line: 18, column: 3, scope: !4)
-// CHECK:STDOUT: !8 = !DILocation(line: 19, column: 3, scope: !4)
-// CHECK:STDOUT: !9 = !DILocation(line: 20, column: 3, scope: !4)
-// CHECK:STDOUT: !10 = !DILocation(line: 17, column: 1, scope: !4)
+// CHECK:STDOUT: !7 = !DILocation(line: 20, column: 3, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 21, column: 3, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 22, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = !DILocation(line: 19, column: 1, scope: !4)
diff --git a/toolchain/testing/file_test.cpp b/toolchain/testing/file_test.cpp
index a18efc49cd99..b64c44fbceb6 100644
--- a/toolchain/testing/file_test.cpp
+++ b/toolchain/testing/file_test.cpp
@@ -63,19 +63,14 @@ class ToolchainFileTest : public FileTestBase {
   }
 
  private:
-  // The prelude mode. For lex and parse, it's always `None`; we exclude it in
-  // order to focus errors. For check and lowering, it's set through
-  // `min_prelude` and `no_prelude` subdirectories.
+  // The prelude mode. For lex and parse, it's always `Default`. For check and
+  // lowering, it's set through `min_prelude` subdirectories.
+  // TODO: Remove `min_prelude` subdirectory support.
   enum Prelude {
     Default,
     Min,
-    None,
   };
   auto prelude() const -> Prelude {
-    if (component_ == "lex" || component_ == "parse" ||
-        test_name().find("/no_prelude/") != llvm::StringRef::npos) {
-      return Prelude::None;
-    }
     if (test_name().find("/min_prelude/") != llvm::StringRef::npos) {
       return Prelude::Min;
     }
@@ -134,9 +129,11 @@ auto ToolchainFileTest::Run(
     llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem>& fs,
     FILE* input_stream, llvm::raw_pwrite_stream& output_stream,
     llvm::raw_pwrite_stream& error_stream) const -> ErrorOr<RunResult> {
-  CARBON_ASSIGN_OR_RETURN(auto prelude_files,
-                          installation_.ReadPreludeManifest());
-  if (prelude() == Prelude::Default) {
+  llvm::SmallVector<std::string> prelude_files;
+  // Lex and parse shouldn't ever access the prelude.
+  if (component_ != "lex" && component_ != "parse") {
+    // TODO: Try providing the prelude as an overlay.
+    CARBON_ASSIGN_OR_RETURN(prelude_files, installation_.ReadPreludeManifest());
     for (const auto& file : prelude_files) {
       CARBON_RETURN_IF_ERROR(AddFile(*fs, file));
     }
@@ -188,9 +185,10 @@ auto ToolchainFileTest::GetDefaultArgs() const
   args.insert(args.end(), {"compile", "--phase=" + component_.str()});
 
   if (component_ == "lex") {
-    args.insert(args.end(), {"--dump-tokens", "--omit-file-boundary-tokens"});
+    args.insert(args.end(), {"--no-prelude-import", "--dump-tokens",
+                             "--omit-file-boundary-tokens"});
   } else if (component_ == "parse") {
-    args.push_back("--dump-parse-tree");
+    args.insert(args.end(), {"--no-prelude-import", "--dump-parse-tree"});
   } else if (component_ == "check") {
     args.insert(args.end(), {"--dump-sem-ir", "--dump-sem-ir-ranges=only"});
   } else if (component_ == "lower") {
@@ -214,10 +212,6 @@ auto ToolchainFileTest::GetDefaultArgs() const
       args.insert(args.end(), {"--custom-core",
                                "--exclude-dump-file-prefix=include_files/"});
       break;
-
-    case Prelude::None:
-      args.push_back("--no-prelude-import");
-      break;
   }
 
   args.push_back("%s");